<PAGE>   1

    As filed with the Securities and Exchange Commission on January 20, 2000
                                              Registration No. 333-_____________

================================================================================

                       SECURITIES AND EXCHANGE COMMISSION

                             Washington, D.C. 20549

                                -----------------
                                    FORM S-8
                             REGISTRATION STATEMENT
                                      Under
                           The Securities Act of 1933

                                -----------------

                                DOUBLECLICK INC.
               (Exact name of issuer as specified in its charter)

                DELAWARE                                   13-3870996
     (State or other jurisdiction              (IRS Employer Identification No.)
   of incorporation or organization)

                               450 W. 33RD STREET
                            NEW YORK, NEW YORK 10001
               (Address of principal executive offices) (Zip Code)

                                -----------------
                             DOUBLECLICK 401(k) PLAN
               NETGRAVITY, INC. 1998 EMPLOYEE STOCK PURCHASE PLAN
                            (Full title of the plan)

                                -----------------
                                KEVIN J. O'CONNOR
         CHIEF EXECUTIVE OFFICER AND CHAIRMAN OF THE BOARD OF DIRECTORS
                                DOUBLECLICK INC.
                               450 W. 33RD STREET
                            NEW YORK, NEW YORK 10001
                     (Name and address of agent for service)
                                 (212) 683-0001
          (Telephone number, including area code, of agent for service)

                                -----------------
                         CALCULATION OF REGISTRATION FEE

<TABLE>
<CAPTION>
                                     Amount to be   Offering Price     Aggregate         Amount of
   Title of Securities to be          Registered       per Share    Offering Price     Registration
           Registered                     (1)             (2)             (2)               Fee
   -------------------------         ------------   --------------  --------------     ------------
<S>                                 <C>             <C>             <C>                <C>
 DoubleClick Inc. 401(k) Plan
 Common Stock, $0.001 par
   value (3)                           400,000         $120.55       $48,220,000.00      $12,730.08

 NetGravity, Inc.
 1998 Employee Stock Purchase
   Plan Common Stock, $0.001
   par value(4)                         60,000         $ 14.21       $   852,600.00      $   225.09
                                                                                         ----------
 Aggregate Registration Fee                                                              $12,955.17

</TABLE>

(1) This Registration Statement shall also cover any additional shares of
    Registrant's Common Stock which become issuable under Registrant's 401(k)
    Plan by reason of any stock dividend, stock split, recapitalization or other
    similar transaction effected without the Registrant's receipt of
    consideration which results in an increase in the number of the Registrant's
    outstanding shares of Common Stock.


<PAGE>   2

(2) Calculated solely for purposes of this offering under Rule 457(h) of the
    Securities Act of 1933, as amended, on the basis of the average of the high
    and low selling prices per share of the Registrant's Common Stock on
    January 19, 2000 as reported by the Nasdaq National Market.

(3) In addition, pursuant to Rule 416(c) of the Securities Act of 1933, this
    Registration Statement also covers an indeterminate amount of interests to
    be offered or sold pursuant to the DoubleClick Inc. 401(k) Plan.

(4) Calculated solely for purposes of this offering under Rule 457(h) of the
    Securities Act of 1933, as amended, on the basis of the weighted average
    exercise price of the outstanding options.

<PAGE>   3

                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3. Incorporation of Certain Documents by Reference

        DoubleClick Inc. (the "Registrant") hereby incorporates by reference
into this Registration Statement the following documents previously filed with
the Securities and Exchange Commission (the "SEC"):

        (a)    The Registrant's Annual Report on Form 10-K for the fiscal year
               ended December 31, 1998 filed with the SEC on March 4, 1999 and
               the Amendments on Form 10-K/A filed with the SEC on April 27,
               1999 and October 15, 1999;

        (b)    The Registrant's Current Reports on Form 8-K filed with the SEC
               on March 15, 1999 (for event dates January 20, 1999 and March 11,
               1999, respectively), June 17, 1999 (for event date June 13,
               1999), July 22, 1999 (for event date July 12, 1999), November 10,
               1999 (for event date October 26, 1999, as amended by Form 8-K/A
               filed on January 10, 2000), December 8, 1999 (for event date
               November 23, 1999, as amended by Form 8-K/A filed on January 10,
               2000) and January 13, 2000 (for event date December 29, 1999);

        (c)    The Registrant's Quarterly Reports on Form 10-Q for the periods
               ending March 31, 1999, June 30, 1999 and September 30, 1999 filed
               with the SEC on May 14, 1999, August 13, 1999 and November 15,
               1999, respectively, as amended by Amendment No. 1 on Form 10-Q/A
               (for period ending March 31, 1999) and as amended by Amendment
               No. 1 on Form 10-Q/A (for period ending June 30, 1999),
               respectively, filed with the SEC on October 15, 1999; and

        (d)    The Registrant's Registration Statement No. 000-23709 on Form 8-A
               filed with the SEC on February 2, 1998 and amended on February 9,
               1998 and December 1, 1998, in which there is described the terms,
               rights and provisions applicable to the Registrant's outstanding
               Common Stock.

        All reports and definitive proxy or information statements filed
pursuant to Section 13(a), 13(c), 14 or 15(d) of the Securities Exchange Act of
1934 (the "1934 Act") after the date of this Registration Statement and prior to
the filing of a post-effective amendment which indicates that all securities
offered hereby have been sold or which deregisters all securities then remaining
unsold shall be deemed to be incorporated by reference into this Registration
Statement and to be a part hereof from the date of filing of such documents. Any
statement contained in a document incorporated or deemed to be incorporated by
reference herein shall be deemed to be modified or superseded for purposes of
this Registration Statement to the extent that a statement contained herein or
in any subsequently filed document which also is deemed to be incorporated by
reference herein modifies or supersedes such statement. Any such statement so
modified or superseded shall not be deemed, except as so modified or superseded,
to constitute a part of this Registration Statement.

Item 4. Description of Capital Stock

        Inapplicable.


                                      II-1
<PAGE>   4

Item 5. Interests of Named Experts and Counsel

        Inapplicable.

Item 6. Indemnification of Directors and Officers

        The Registrant's Certificate of Incorporation (the "Certificate")
provides that, except to the extent prohibited by the Delaware General
Corporation Law(the "DGCL"), the Registrant's directors shall not be personally
liable to the Registrant or its stockholders for monetary damages for any breach
of fiduciary duty as directors of the Registrant. Under the DGCL, the directors
have a fiduciary duty to the Registrant which is not eliminated by this
provision of the Certificate and, in appropriate circumstances, equitable
remedies such as injunctive or other forms of nonmonetary relief will remain
available. In addition, each director will continue to be subject to liability
under the DGCL for breach of the director's duty of loyalty to the Registrant,
for acts or omissions which are found by a court of competent jurisdiction to be
not in good faith or involving intentional misconduct, for knowing violations of
law, for actions leading to improper personal benefit to the director, and for
payment of dividends or approval of stock repurchases or redemptions that are
prohibited by DGCL. This provision also does not affect the directors'
responsibilities under any other laws, such as the Federal securities laws or
state or Federal environmental laws. The Registrant has obtained liability
insurance for its officers and directors.

        Section 145 of the DGCL empowers a corporation to indemnify its
directors and officers and to purchase insurance with respect to liability
arising out of their capacity or status as directors and officers, provided that
this provision shall not eliminate or limit the liability of a director: (i) for
any breach of the director's duty of loyalty to the corporation or its
stockholders, (ii) for acts or omissions not in good faith or which involve
intentional misconduct or a knowing violation of law, (iii) arising under
Section 174 of the DGCL, or (iv)for any transaction from which the director
derived an improper personal benefit. The DGCL provides further that the
indemnification permitted thereunder shall not be deemed exclusive of any other
rights to which the directors and officers may be entitled under the
corporation's bylaws, any agreement, a vote of stockholders or otherwise. The
Certificate eliminates the personal liability of directors to the fullest extent
permitted by Section 102(b)(7) of the DGCL and provides that the Registrant
shall fully indemnify any person who was or is a party or is threatened to be
made a party to any threatened, pending or completed action, suit or proceeding
(whether civil, criminal, administrative or investigative) by reason of the fact
that such person is or was a director or officer of the Registrant, or is or was
serving at the request of the Registrant as a director or officer of another
corporation, partnership, joint venture, trust, employee benefit plan or other
enterprise, against expenses (including attorney's fees), judgments, fines and
amounts paid in settlement actually and reasonably incurred by such person in
connection with such action, suit or proceeding.

        At present, there is no pending litigation or proceeding involving any
director, officer, employee or agent as to which indemnification will be
required or permitted under the Certificate. The Registrant is not aware of any
threatened litigation or proceeding that may result in a claim for such
indemnification.


                                      II-2
<PAGE>   5

Item 7. Exemption from Registration Claimed

        Inapplicable.

Item 8. Exhibits

<TABLE>
<CAPTION>
Exhibit
Number       Exhibit
-------      -------
<S>          <C>
   4.0       Instruments Defining Rights of Stockholders. Reference is made to
             Registrant's Registration Statement No. 000-23709 on Form 8-A, and the exhibits
             thereto, which are incorporated herein by reference pursuant to Item 3(d) of
             this Registration Statement.

   5.0       Opinion of Brobeck, Phleger & Harrison LLP.

  23.1       Consent of PricewaterhouseCoopers LLP, New York, New York, Independent Accountants.

  23.2       Consent of PricewaterhouseCoopers LLP, Broomfield, Colorado, Independent Accountants.

  23.3       Consent of KPMG LLP, Independent Accountants.

  23.4       Consent of Brobeck, Phleger & Harrison LLP is contained in Exhibit 5.

  24.0       Power of Attorney. Reference is made to page II-5 of this Registration Statement.

  99.1       NetGravity, Inc. 1998 Employee Stock Purchase Plan.
</TABLE>

        The undersigned Registrant hereby undertakes that it will submit the
DoubleClick Inc. 401(k) Plan to the Internal Revenue Service ("IRS") in a timely
manner and has or will make all changes required by the IRS in order to qualify
the plan under Section 401 of the Internal Revenue Code.

Item 9. Undertakings

        A. The undersigned Registrant hereby undertakes: (1) to file, during any
period in which offers or sales are being made, a post-effective amendment to
this Registration Statement; (i) to include any prospectus required by Section
10(a)(3) of the Securities Act of 1933, as amended (the "1933 Act"), (ii) to
reflect in the prospectus any facts or events arising after the effective date
of this Registration Statement (or the most recent post-effective amendment
thereof) which, individually or in the aggregate, represent a fundamental change
in the information set forth in this Registration Statement, and (iii) to
include any material information with respect to the plan of distribution not
previously disclosed in this Registration Statement or any material change to
such information in this Registration Statement; provided, however, that clauses
(1)(i) and (1)(ii) shall not apply if the information required to be included in
a post-effective amendment by those paragraphs is contained in periodic reports
filed by the Registrant pursuant to Section 13 or Section 15(d) of the 1934 Act
that are incorporated by reference into the registration statement; (2) that for
the purpose of determining any liability under the 1933 Act each such
post-effective amendment shall be deemed to be a new registration statement
relating to the securities offered therein, and the offering of such securities
at that time shall be deemed to be the initial bona fide offering thereof; and
(3) to remove from registration by means of a post-effective amendment any of
the securities being registered which remain unsold upon the termination of the
DoubleClick Inc. 401(k) Plan or the NetGravity, Inc. 1998 Employee Stock
Purchase Plan.

        B. The undersigned Registrant hereby undertakes that, for purposes of
determining any liability under the 1933 Act, each filing of the Registrant's
annual report pursuant to Section 13(a) or Section 15(d) of the 1934 Act (and,
where applicable, each filing of


                                      II-3
<PAGE>   6

an employee benefit plan's annual report pursuant to Section 15(d) of the
Securities and Exchange Act of 1934) that is incorporated by reference into this
Registration Statement shall be deemed to be a new registration statement
relating to the securities offered therein, and the offering of such securities
at that time shall be deemed to be the initial bona fide offering thereof.

        C. Insofar as indemnification for liabilities arising under the 1933 Act
may be permitted to directors, officers and controlling persons of the
Registrant pursuant to the indemnification provisions summarized in Item 6
above, or otherwise, the Registrant has been advised that in the opinion of the
SEC such indemnification is against public policy as expressed in the 1933 Act
and is, therefore, unenforceable. In the event that a claim for indemnification
against such liabilities (other than the payment by the Registrant of expenses
incurred or paid by a director, officer or controlling person of the Registrant
in the successful defense of any action, suit or proceeding) is asserted by such
director, officer or controlling person in connection with the securities being
registered, the Registrant will, unless in the opinion of its counsel the matter
has been settled by controlling precedent, submit to a court of appropriate
jurisdiction the question whether such indemnification by it is against public
policy as expressed in the 1933 Act and will be governed by the final
adjudication of such issue.


                                      II-4
<PAGE>   7

                                   SIGNATURES

Registrant.

        Pursuant to the requirements of the Securities Act of 1933, as amended,
the Registrant certifies that it has reasonable grounds to believe that it meets
all of the requirements for filing on Form S-8 and has duly caused this
Registration Statement to be signed on its behalf by the undersigned, thereunto
duly authorized, in the City of New York, State of New York, on this 20th day of
January, 2000.


                                           DOUBLECLICK INC.


                                           By: /s/ KEVIN J. O'CONNOR
                                              ----------------------------------
                                              Kevin J. O'Connor
                                              Chief Executive Officer and
                                              Chairman of the Board of Directors


                                POWER OF ATTORNEY

KNOW ALL MEN BY THESE PRESENTS:

        That the undersigned officers and directors of DoubleClick Inc., a
Delaware corporation, do hereby constitute and appoint Kevin J. O'Connor and
Stephen R. Collins, the lawful attorneys and agents, with full power and
authority to do any and all acts and things and to execute any and all
instruments which said attorney and agent determines may be necessary or
advisable or required to enable said corporation to comply with the Securities
Act of 1933, as amended, and any rules or regulations or requirements of the
Securities and Exchange Commission in connection with this Registration
Statement. Without limiting the generality of the foregoing power and authority,
the powers granted include the power and authority to sign the names of the
undersigned officers and directors in the capacities indicated below to this
Registration Statement, to any and all amendments, both pre-effective and
post-effective, and supplements to this Registration Statement, and to any and
all instruments or documents filed as part of or in conjunction with this
Registration Statement or amendments or supplements thereof, and each of the
undersigned hereby ratifies and confirms all that said attorneys and agents, or
any of them, shall do or cause to be done by virtue hereof. This Power of
Attorney may be signed in several counterparts.

<PAGE>   8

        IN WITNESS WHEREOF, each of the undersigned has executed this Power of
Attorney as of the date indicated.

        Pursuant to the requirements of the Securities Act of 1933, as amended,
this Registration Statement has been signed below by the following persons in
the capacities and on the dates indicated.

<TABLE>
<CAPTION>
           SIGNATURES                               TITLE                           DATE
           ----------                               -----                           ----
<S>                                <C>                                        <C>
/s/ KEVIN J. O'CONNOR              Chief Executive Officer and Chairman       January 20, 2000
-----------------------------      of the Board (Principal Executive
Kevin J. O'Connor                  Officer)

                                   Chief Financial Officer                    __________, 2000
-----------------------------
Stephen R. Collins

/s/ DAVID N. STROHM                Director                                   January 20, 2000
-----------------------------
David N. Strohm

                                   Director                                   __________, 2000
-----------------------------
Mark E. Nunnelley

/s/ W. GRANT GREGORY               Director                                   January 20, 2000
-----------------------------
W. Grant Gregory

/s/ Don Peppers                    Director                                   January 20, 2000
-----------------------------
Don Peppers

                                   Director                                   __________, 2000
-----------------------------
Thomas S. Murphy
</TABLE>

<PAGE>   9

Plan.

        Pursuant to the requirements of the Securities Act of 1933, the
DoubleClick Inc. 401(k) Plan has caused this Registration Statement to be signed
on its behalf by the undersigned, thereunto duly authorized, in the City of New
York, State of New York, on this 20th day of January, 2000.


                                            DoubleClick Inc. 401(k) Plan



                                            By: /s/ KEVIN J. O'CONNOR
                                               ---------------------------------
<PAGE>   10


                                  EXHIBIT INDEX

<TABLE>
<CAPTION>
Exhibit
Number       Exhibit
-------      -------
<S>          <C>
   4.0       Instruments Defining Rights of Stockholders. Reference is made to
             Registrant's Registration Statement No. 000-23709 on Form 8-A, and the exhibits
             thereto, which are incorporated herein by reference pursuant to Item 3(d) of
             this Registration Statement.

   5.0       Opinion of Brobeck, Phleger & Harrison LLP.

  23.1       Consent of PricewaterhouseCoopers LLP, New York, New York, Independent Accountants.

  23.2       Consent of PricewaterhouseCoopers LLP, Broomfield, Colorado, Independent Accountants.

  23.3       Consent of KPMG LLP, Independent Accountants.

  23.4       Consent of Brobeck, Phleger & Harrison LLP is contained in Exhibit 5.

  24.0       Power of Attorney. Reference is made to page II-5 of this Registration Statement.

  99.1       NetGravity, Inc. 1998 Employee Stock Purchase Plan.
</TABLE>
[{"type": "S-8", "sequence": "1", "description": "FORM S-8", "secsgml_size_bytes": 21728}]
{"company-data": {"conformed-name": "DOUBLECLICK INC", "cik": "0001049480", "assigned-sic": "7310", "irs-number": "133870996", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-95105", "film-number": "510543"}, "business-address": {"street1": "450 W 33RD ST", "street2": "32ND FL", "city": "NEW YORK", "state": "NY", "zip": "10001", "phone": "2126830001"}, "mail-address": {"street1": "450 W 33RD ST", "city": "NEW YORK", "state": "NY", "zip": "10001"}}
1

    As filed with the Securities and Exchange Commission on January 20, 2000
                                              Registration No. 333-_____________

================================================================================

                       SECURITIES AND EXCHANGE COMMISSION

                             Washington, D.C. 20549

                                -----------------
                                    FORM S-8
                             REGISTRATION STATEMENT
                                      Under
                           The Securities Act of 1933

                                -----------------

                                DOUBLECLICK INC.
               (Exact name of issuer as specified in its charter)

                DELAWARE                                   13-3870996
     (State or other jurisdiction              (IRS Employer Identification No.)
   of incorporation or organization)

                               450 W. 33RD STREET
                            NEW YORK, NEW YORK 10001
               (Address of principal executive offices) (Zip Code)

                                -----------------
                             DOUBLECLICK 401(k) PLAN
               NETGRAVITY, INC. 1998 EMPLOYEE STOCK PURCHASE PLAN
                            (Full title of the plan)

                                -----------------
                                KEVIN J. O'CONNOR
         CHIEF EXECUTIVE OFFICER AND CHAIRMAN OF THE BOARD OF DIRECTORS
                                DOUBLECLICK INC.
                               450 W. 33RD STREET
                            NEW YORK, NEW YORK 10001
                     (Name and address of agent for service)
                                 (212) 683-0001
          (Telephone number, including area code, of agent for service)

                                -----------------
                         CALCULATION OF REGISTRATION FEE
Amount to be   Offering Price     Aggregate         Amount of
   Title of Securities to be          Registered       per Share    Offering Price     Registration
           Registered                     (1)             (2)             (2)               Fee
   -------------------------         ------------   --------------  --------------     ------------
DoubleClick Inc. 401(k) Plan
 Common Stock, $0.001 par
   value (3)                           400,000         $120.55       $48,220,000.00      $12,730.08

 NetGravity, Inc.
 1998 Employee Stock Purchase
   Plan Common Stock, $0.001
   par value(4)                         60,000         $ 14.21       $   852,600.00      $   225.09
                                                                                         ----------
 Aggregate Registration Fee                                                              $12,955.17
(1) This Registration Statement shall also cover any additional shares of
    Registrant's Common Stock which become issuable under Registrant's 401(k)
    Plan by reason of any stock dividend, stock split, recapitalization or other
    similar transaction effected without the Registrant's receipt of
    consideration which results in an increase in the number of the Registrant's
    outstanding shares of Common Stock.
2

(2) Calculated solely for purposes of this offering under Rule 457(h) of the
    Securities Act of 1933, as amended, on the basis of the average of the high
    and low selling prices per share of the Registrant's Common Stock on
    January 19, 2000 as reported by the Nasdaq National Market.

(3) In addition, pursuant to Rule 416(c) of the Securities Act of 1933, this
    Registration Statement also covers an indeterminate amount of interests to
    be offered or sold pursuant to the DoubleClick Inc. 401(k) Plan.

(4) Calculated solely for purposes of this offering under Rule 457(h) of the
    Securities Act of 1933, as amended, on the basis of the weighted average
    exercise price of the outstanding options.
3

                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3. Incorporation of Certain Documents by Reference

        DoubleClick Inc. (the "Registrant") hereby incorporates by reference
into this Registration Statement the following documents previously filed with
the Securities and Exchange Commission (the "SEC"):

        (a)    The Registrant's Annual Report on Form 10-K for the fiscal year
               ended December 31, 1998 filed with the SEC on March 4, 1999 and
               the Amendments on Form 10-K/A filed with the SEC on April 27,
               1999 and October 15, 1999;

        (b)    The Registrant's Current Reports on Form 8-K filed with the SEC
               on March 15, 1999 (for event dates January 20, 1999 and March 11,
               1999, respectively), June 17, 1999 (for event date June 13,
               1999), July 22, 1999 (for event date July 12, 1999), November 10,
               1999 (for event date October 26, 1999, as amended by Form 8-K/A
               filed on January 10, 2000), December 8, 1999 (for event date
               November 23, 1999, as amended by Form 8-K/A filed on January 10,
               2000) and January 13, 2000 (for event date December 29, 1999);

        (c)    The Registrant's Quarterly Reports on Form 10-Q for the periods
               ending March 31, 1999, June 30, 1999 and September 30, 1999 filed
               with the SEC on May 14, 1999, August 13, 1999 and November 15,
               1999, respectively, as amended by Amendment No. 1 on Form 10-Q/A
               (for period ending March 31, 1999) and as amended by Amendment
               No. 1 on Form 10-Q/A (for period ending June 30, 1999),
               respectively, filed with the SEC on October 15, 1999; and

        (d)    The Registrant's Registration Statement No. 000-23709 on Form 8-A
               filed with the SEC on February 2, 1998 and amended on February 9,
               1998 and December 1, 1998, in which there is described the terms,
               rights and provisions applicable to the Registrant's outstanding
               Common Stock.

        All reports and definitive proxy or information statements filed
pursuant to Section 13(a), 13(c), 14 or 15(d) of the Securities Exchange Act of
1934 (the "1934 Act") after the date of this Registration Statement and prior to
the filing of a post-effective amendment which indicates that all securities
offered hereby have been sold or which deregisters all securities then remaining
unsold shall be deemed to be incorporated by reference into this Registration
Statement and to be a part hereof from the date of filing of such documents. Any
statement contained in a document incorporated or deemed to be incorporated by
reference herein shall be deemed to be modified or superseded for purposes of
this Registration Statement to the extent that a statement contained herein or
in any subsequently filed document which also is deemed to be incorporated by
reference herein modifies or supersedes such statement. Any such statement so
modified or superseded shall not be deemed, except as so modified or superseded,
to constitute a part of this Registration Statement.

Item 4. Description of Capital Stock

        Inapplicable.

                                      II-1
4

Item 5. Interests of Named Experts and Counsel

        Inapplicable.

Item 6. Indemnification of Directors and Officers

        The Registrant's Certificate of Incorporation (the "Certificate")
provides that, except to the extent prohibited by the Delaware General
Corporation Law(the "DGCL"), the Registrant's directors shall not be personally
liable to the Registrant or its stockholders for monetary damages for any breach
of fiduciary duty as directors of the Registrant. Under the DGCL, the directors
have a fiduciary duty to the Registrant which is not eliminated by this
provision of the Certificate and, in appropriate circumstances, equitable
remedies such as injunctive or other forms of nonmonetary relief will remain
available. In addition, each director will continue to be subject to liability
under the DGCL for breach of the director's duty of loyalty to the Registrant,
for acts or omissions which are found by a court of competent jurisdiction to be
not in good faith or involving intentional misconduct, for knowing violations of
law, for actions leading to improper personal benefit to the director, and for
payment of dividends or approval of stock repurchases or redemptions that are
prohibited by DGCL. This provision also does not affect the directors'
responsibilities under any other laws, such as the Federal securities laws or
state or Federal environmental laws. The Registrant has obtained liability
insurance for its officers and directors.

        Section 145 of the DGCL empowers a corporation to indemnify its
directors and officers and to purchase insurance with respect to liability
arising out of their capacity or status as directors and officers, provided that
this provision shall not eliminate or limit the liability of a director: (i) for
any breach of the director's duty of loyalty to the corporation or its
stockholders, (ii) for acts or omissions not in good faith or which involve
intentional misconduct or a knowing violation of law, (iii) arising under
Section 174 of the DGCL, or (iv)for any transaction from which the director
derived an improper personal benefit. The DGCL provides further that the
indemnification permitted thereunder shall not be deemed exclusive of any other
rights to which the directors and officers may be entitled under the
corporation's bylaws, any agreement, a vote of stockholders or otherwise. The
Certificate eliminates the personal liability of directors to the fullest extent
permitted by Section 102(b)(7) of the DGCL and provides that the Registrant
shall fully indemnify any person who was or is a party or is threatened to be
made a party to any threatened, pending or completed action, suit or proceeding
(whether civil, criminal, administrative or investigative) by reason of the fact
that such person is or was a director or officer of the Registrant, or is or was
serving at the request of the Registrant as a director or officer of another
corporation, partnership, joint venture, trust, employee benefit plan or other
enterprise, against expenses (including attorney's fees), judgments, fines and
amounts paid in settlement actually and reasonably incurred by such person in
connection with such action, suit or proceeding.

        At present, there is no pending litigation or proceeding involving any
director, officer, employee or agent as to which indemnification will be
required or permitted under the Certificate. The Registrant is not aware of any
threatened litigation or proceeding that may result in a claim for such
indemnification.

                                      II-2
5

Item 7. Exemption from Registration Claimed

        Inapplicable.

Item 8. Exhibits
Exhibit
Number       Exhibit
-------      -------
4.0       Instruments Defining Rights of Stockholders. Reference is made to
             Registrant's Registration Statement No. 000-23709 on Form 8-A, and the exhibits
             thereto, which are incorporated herein by reference pursuant to Item 3(d) of
             this Registration Statement.

   5.0       Opinion of Brobeck, Phleger & Harrison LLP.

  23.1       Consent of PricewaterhouseCoopers LLP, New York, New York, Independent Accountants.

  23.2       Consent of PricewaterhouseCoopers LLP, Broomfield, Colorado, Independent Accountants.

  23.3       Consent of KPMG LLP, Independent Accountants.

  23.4       Consent of Brobeck, Phleger & Harrison LLP is contained in Exhibit 5.

  24.0       Power of Attorney. Reference is made to page II-5 of this Registration Statement.

  99.1       NetGravity, Inc. 1998 Employee Stock Purchase Plan.
The undersigned Registrant hereby undertakes that it will submit the
DoubleClick Inc. 401(k) Plan to the Internal Revenue Service ("IRS") in a timely
manner and has or will make all changes required by the IRS in order to qualify
the plan under Section 401 of the Internal Revenue Code.

Item 9. Undertakings

        A. The undersigned Registrant hereby undertakes: (1) to file, during any
period in which offers or sales are being made, a post-effective amendment to
this Registration Statement; (i) to include any prospectus required by Section
10(a)(3) of the Securities Act of 1933, as amended (the "1933 Act"), (ii) to
reflect in the prospectus any facts or events arising after the effective date
of this Registration Statement (or the most recent post-effective amendment
thereof) which, individually or in the aggregate, represent a fundamental change
in the information set forth in this Registration Statement, and (iii) to
include any material information with respect to the plan of distribution not
previously disclosed in this Registration Statement or any material change to
such information in this Registration Statement; provided, however, that clauses
(1)(i) and (1)(ii) shall not apply if the information required to be included in
a post-effective amendment by those paragraphs is contained in periodic reports
filed by the Registrant pursuant to Section 13 or Section 15(d) of the 1934 Act
that are incorporated by reference into the registration statement; (2) that for
the purpose of determining any liability under the 1933 Act each such
post-effective amendment shall be deemed to be a new registration statement
relating to the securities offered therein, and the offering of such securities
at that time shall be deemed to be the initial bona fide offering thereof; and
(3) to remove from registration by means of a post-effective amendment any of
the securities being registered which remain unsold upon the termination of the
DoubleClick Inc. 401(k) Plan or the NetGravity, Inc. 1998 Employee Stock
Purchase Plan.

        B. The undersigned Registrant hereby undertakes that, for purposes of
determining any liability under the 1933 Act, each filing of the Registrant's
annual report pursuant to Section 13(a) or Section 15(d) of the 1934 Act (and,
where applicable, each filing of

                                      II-3
6

an employee benefit plan's annual report pursuant to Section 15(d) of the
Securities and Exchange Act of 1934) that is incorporated by reference into this
Registration Statement shall be deemed to be a new registration statement
relating to the securities offered therein, and the offering of such securities
at that time shall be deemed to be the initial bona fide offering thereof.

        C. Insofar as indemnification for liabilities arising under the 1933 Act
may be permitted to directors, officers and controlling persons of the
Registrant pursuant to the indemnification provisions summarized in Item 6
above, or otherwise, the Registrant has been advised that in the opinion of the
SEC such indemnification is against public policy as expressed in the 1933 Act
and is, therefore, unenforceable. In the event that a claim for indemnification
against such liabilities (other than the payment by the Registrant of expenses
incurred or paid by a director, officer or controlling person of the Registrant
in the successful defense of any action, suit or proceeding) is asserted by such
director, officer or controlling person in connection with the securities being
registered, the Registrant will, unless in the opinion of its counsel the matter
has been settled by controlling precedent, submit to a court of appropriate
jurisdiction the question whether such indemnification by it is against public
policy as expressed in the 1933 Act and will be governed by the final
adjudication of such issue.

                                      II-4
7

                                   SIGNATURES

Registrant.

        Pursuant to the requirements of the Securities Act of 1933, as amended,
the Registrant certifies that it has reasonable grounds to believe that it meets
all of the requirements for filing on Form S-8 and has duly caused this
Registration Statement to be signed on its behalf by the undersigned, thereunto
duly authorized, in the City of New York, State of New York, on this 20th day of
January, 2000.

                                           DOUBLECLICK INC.

                                           By: /s/ KEVIN J. O'CONNOR
                                              ----------------------------------
                                              Kevin J. O'Connor
                                              Chief Executive Officer and
                                              Chairman of the Board of Directors

                                POWER OF ATTORNEY

KNOW ALL MEN BY THESE PRESENTS:

        That the undersigned officers and directors of DoubleClick Inc., a
Delaware corporation, do hereby constitute and appoint Kevin J. O'Connor and
Stephen R. Collins, the lawful attorneys and agents, with full power and
authority to do any and all acts and things and to execute any and all
instruments which said attorney and agent determines may be necessary or
advisable or required to enable said corporation to comply with the Securities
Act of 1933, as amended, and any rules or regulations or requirements of the
Securities and Exchange Commission in connection with this Registration
Statement. Without limiting the generality of the foregoing power and authority,
the powers granted include the power and authority to sign the names of the
undersigned officers and directors in the capacities indicated below to this
Registration Statement, to any and all amendments, both pre-effective and
post-effective, and supplements to this Registration Statement, and to any and
all instruments or documents filed as part of or in conjunction with this
Registration Statement or amendments or supplements thereof, and each of the
undersigned hereby ratifies and confirms all that said attorneys and agents, or
any of them, shall do or cause to be done by virtue hereof. This Power of
Attorney may be signed in several counterparts.
8

        IN WITNESS WHEREOF, each of the undersigned has executed this Power of
Attorney as of the date indicated.

        Pursuant to the requirements of the Securities Act of 1933, as amended,
this Registration Statement has been signed below by the following persons in
the capacities and on the dates indicated.
SIGNATURES                               TITLE                           DATE
           ----------                               -----                           ----
/s/ KEVIN J. O'CONNOR              Chief Executive Officer and Chairman       January 20, 2000
-----------------------------      of the Board (Principal Executive
Kevin J. O'Connor                  Officer)

                                   Chief Financial Officer                    __________, 2000
-----------------------------
Stephen R. Collins

/s/ DAVID N. STROHM                Director                                   January 20, 2000
-----------------------------
David N. Strohm

                                   Director                                   __________, 2000
-----------------------------
Mark E. Nunnelley

/s/ W. GRANT GREGORY               Director                                   January 20, 2000
-----------------------------
W. Grant Gregory

/s/ Don Peppers                    Director                                   January 20, 2000
-----------------------------
Don Peppers

                                   Director                                   __________, 2000
-----------------------------
Thomas S. Murphy
9

Plan.

        Pursuant to the requirements of the Securities Act of 1933, the
DoubleClick Inc. 401(k) Plan has caused this Registration Statement to be signed
on its behalf by the undersigned, thereunto duly authorized, in the City of New
York, State of New York, on this 20th day of January, 2000.

                                            DoubleClick Inc. 401(k) Plan

                                            By: /s/ KEVIN J. O'CONNOR
                                               ---------------------------------
10

                                  EXHIBIT INDEX
Exhibit
Number       Exhibit
-------      -------
4.0       Instruments Defining Rights of Stockholders. Reference is made to
             Registrant's Registration Statement No. 000-23709 on Form 8-A, and the exhibits
             thereto, which are incorporated herein by reference pursuant to Item 3(d) of
             this Registration Statement.

   5.0       Opinion of Brobeck, Phleger & Harrison LLP.

  23.1       Consent of PricewaterhouseCoopers LLP, New York, New York, Independent Accountants.

  23.2       Consent of PricewaterhouseCoopers LLP, Broomfield, Colorado, Independent Accountants.

  23.3       Consent of KPMG LLP, Independent Accountants.

  23.4       Consent of Brobeck, Phleger & Harrison LLP is contained in Exhibit 5.

  24.0       Power of Attorney. Reference is made to page II-5 of this Registration Statement.

  99.1       NetGravity, Inc. 1998 Employee Stock Purchase Plan.