<PAGE>   1
     As filed with the Securities and Exchange Commission on June 28, 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 registrant as specified in its charter)

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

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

                   FLASHBASE, INC. 1999 EQUITY INCENTIVE PLAN
                           (Full title of the Plan(s))
                              ___________________

                                KEVIN J. O'CONNOR
         CHIEF EXECUTIVE OFFICER AND CHAIRMAN OF THE BOARD OF DIRECTORS
                                DOUBLECLICK INC.
                              450 WEST 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>
================================================================================================================
                                                    Proposed Maximum       Proposed Maximum        Amount of
Title of Securities to be        Amount to be      Offering Price per     Aggregate Offering     Registration
Registered                       Registered(1)           Share(2)               Price(2)               Fee
----------                       -------------     ------------------     ------------------     ------------
<S>                              <C>               <C>                    <C>                    <C>
Flashbase, Inc.                  32,296 shares            $2.15               $69,436.40            $18.33
1999 Equity Incentive Plan
Common Stock, $0.001 par value

---------------------------------------------------------------------------------------------------------------
</TABLE>

(1)   This Registration Statement shall also cover any additional shares of
      Common Stock which become issuable under the Flashbase, Inc. 1999 Equity
      Incentive 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 outstanding shares of Registrant's Common Stock.

(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
      weighted exercise price per share of the Registrant's Common Stock.



<PAGE>   2

                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3. Incorporation of 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 "Commission"):

      (a)   The Registrant's Annual Report on Form 10-K filed with the
            Commission on February 17, 2000 for the fiscal year ended 1999;

      (b)   The Registrant's Quarterly Reports on Form 10-Q, filed with the
            Commission on May 12, 2000 for period ended March 31, 2000;

      (c)   The Registrant's Current Reports on Form 8-K, filed with the
            Commission on November 10, 1999 (as amended on Form 8-K/A filed with
            the Commission on January 10, 2000), December 8, 1999 (as amended on
            Form 8-K/A filed with the Commission on January 10, 2000), January
            13, 2000 (as amended on Form 8-K/A filed with the Commission on
            March 10, 2000), January 27, 2000 (for period dates November 1, 1999
            and January 11, 2000), February 16, 2000, March 17, 2000 and June
            26, 2000; and

      (d)   The Registrant's Registration Statement No. 000-23709 on Form 8-A
            filed with the Commission on February 2, 1998 and amended on
            February 9, 1998 and December 1, 1998, pursuant to Section 12(g) of
            the Securities Exchange Act of 1934 (the "Exchange Act"), 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, as
amended (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 de-registers 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 Securities

      Not applicable.

Item 5. Interests of Named Experts and Counsel

      Not applicable.

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 non



                                      II-1
<PAGE>   3

monetary 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.

Item 7. Exemption from Registration Claimed

      Not applicable.

Item 8. Exhibits

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

       5          Opinion and consent of Brobeck, Phleger & Harrison LLP.

      23.1        Consent of PricewaterhouseCoopers LLP, Independent
                  Accountants.

      23.2        Consent of KPMG LLP, Independent Accountants

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

      24          Power of Attorney. Reference is made to page II-4 of this
                  Registration Statement.

      99.1        Flashbase, Inc. 1999 Equity Incentive Plan.

      99.2        Form of Assumption Agreement
</TABLE>

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 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,



                                      II-2
<PAGE>   4

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 clauses 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 this 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 at the termination of the
Registrant's Flashbase, Inc. 1999 Equity Incentive 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 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 or controlling persons of the
Registrant pursuant to the indemnification provisions summarized in Item 6 or
otherwise, the Registrant has been advised that, in the opinion of the
Commission, 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-3
<PAGE>   5

                                   SIGNATURES

      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 23rd day of
June, 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 PERSONS BY THESE PRESENTS:

      That the undersigned officers and directors of DoubleClick Inc., a
Delaware corporation, do hereby constitute and appoint Kevin J. O'Connor, Chief
Executive Officer and Chairman of the Board of Directors and Stephen R. Collins,
Chief Financial Officer, and each of them, the lawful attorneys-in-fact and
agents with full power and authority to do any and all acts and things and to
execute any and all instruments which said attorneys and agents, and any one of
them, determine 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
that all said attorneys and agents, or any one of them, shall do or cause to be
done by virtue hereof. This Power of Attorney may be signed in several
counterparts.

      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>
           SIGNATURE                               TITLE                            DATE
           ---------                               -----                            ----
<S>                                <C>                                       <C>
/s/ Kevin J. O'Connor              Chief Executive Officer and Chairman       June 23, 2000
-----------------------------      of the Board (Principal Executive
Kevin J. O'Connor                  Officer)


/s/ Stephen R. Collins             Chief Financial Officer (Principal         June 23, 2000
-----------------------------      Financial and Accounting Officer)
Stephen R. Collins
</TABLE>



                                      II-4
<PAGE>   6

<TABLE>
<CAPTION>
           SIGNATURE                               TITLE                            DATE
           ---------                               -----                            ----
<S>                                <C>                                       <C>
/s/ Thomas S. Murphy               Director                                   June 23, 2000
-----------------------------
Thomas S. Murphy


/s/ Mark E. Nunnelly               Director                                   June 23, 2000
-----------------------------
Mark E. Nunnelly


                                   Director                                  ____________, _____
-----------------------------
David N. Strohm


                                   Director                                  ____________, _____
-----------------------------
Dwight A. Merriman


/s/ W. Grant Gregory               Director                                   June 23, 2000
-----------------------------
W. Grant Gregory


/s/ Don Peppers                    Director                                   June 23, 2000
-----------------------------
Don Peppers
</TABLE>



                                      II-5
<PAGE>   7

                                  EXHIBIT INDEX

<TABLE>
<CAPTION>

 Exhibit Number   Exhibit
 --------------   -------

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

       5          Opinion and consent of Brobeck, Phleger & Harrison LLP.

      23.1        Consent of PricewaterhouseCoopers LLP, Independent Accountants.

      23.2        Consent of KPMG LLP, Independent Accountants

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

      24          Power of Attorney. Reference is made to page II-4 of this
                  Registration Statement.

      99.1        Flashbase, Inc. 1999 Equity Incentive Plan.

      99.2        Form of Assumption Agreement
</TABLE>
[{"type": "S-8", "sequence": "1", "filename": "s-8.txt", "description": "FORM S-8", "secsgml_size_bytes": 20223}]
{"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": "333-40310", "film-number": "663448"}, "business-address": {"street1": "450 W 33RD ST", "street2": "16TH FL", "city": "NEW YORK", "state": "NY", "zip": "10001", "phone": "2123815784"}, "mail-address": {"street1": "450 W 33RD ST", "street2": "16TH FL", "city": "NEW YORK", "state": "NY", "zip": "10001"}}
1
     As filed with the Securities and Exchange Commission on June 28, 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 registrant as specified in its charter)

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

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

                   FLASHBASE, INC. 1999 EQUITY INCENTIVE PLAN
                           (Full title of the Plan(s))
                              ___________________

                                KEVIN J. O'CONNOR
         CHIEF EXECUTIVE OFFICER AND CHAIRMAN OF THE BOARD OF DIRECTORS
                                DOUBLECLICK INC.
                              450 WEST 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
================================================================================================================
                                                    Proposed Maximum       Proposed Maximum        Amount of
Title of Securities to be        Amount to be      Offering Price per     Aggregate Offering     Registration
Registered                       Registered(1)           Share(2)               Price(2)               Fee
----------                       -------------     ------------------     ------------------     ------------
Flashbase, Inc.                  32,296 shares            $2.15               $69,436.40            $18.33
1999 Equity Incentive Plan
Common Stock, $0.001 par value

---------------------------------------------------------------------------------------------------------------
(1)   This Registration Statement shall also cover any additional shares of
      Common Stock which become issuable under the Flashbase, Inc. 1999 Equity
      Incentive 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 outstanding shares of Registrant's Common Stock.

(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
      weighted exercise price per share of the Registrant's Common Stock.
2

                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3. Incorporation of 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 "Commission"):

      (a)   The Registrant's Annual Report on Form 10-K filed with the
            Commission on February 17, 2000 for the fiscal year ended 1999;

      (b)   The Registrant's Quarterly Reports on Form 10-Q, filed with the
            Commission on May 12, 2000 for period ended March 31, 2000;

      (c)   The Registrant's Current Reports on Form 8-K, filed with the
            Commission on November 10, 1999 (as amended on Form 8-K/A filed with
            the Commission on January 10, 2000), December 8, 1999 (as amended on
            Form 8-K/A filed with the Commission on January 10, 2000), January
            13, 2000 (as amended on Form 8-K/A filed with the Commission on
            March 10, 2000), January 27, 2000 (for period dates November 1, 1999
            and January 11, 2000), February 16, 2000, March 17, 2000 and June
            26, 2000; and

      (d)   The Registrant's Registration Statement No. 000-23709 on Form 8-A
            filed with the Commission on February 2, 1998 and amended on
            February 9, 1998 and December 1, 1998, pursuant to Section 12(g) of
            the Securities Exchange Act of 1934 (the "Exchange Act"), 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, as
amended (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 de-registers 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 Securities

      Not applicable.

Item 5. Interests of Named Experts and Counsel

      Not applicable.

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 non

                                      II-1
3

monetary 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.

Item 7. Exemption from Registration Claimed

      Not applicable.

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

       5          Opinion and consent of Brobeck, Phleger & Harrison LLP.

      23.1        Consent of PricewaterhouseCoopers LLP, Independent
                  Accountants.

      23.2        Consent of KPMG LLP, Independent Accountants

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

      24          Power of Attorney. Reference is made to page II-4 of this
                  Registration Statement.

      99.1        Flashbase, Inc. 1999 Equity Incentive Plan.

      99.2        Form of Assumption Agreement
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 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,

                                      II-2
4

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 clauses 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 this 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 at the termination of the
Registrant's Flashbase, Inc. 1999 Equity Incentive 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 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 or controlling persons of the
Registrant pursuant to the indemnification provisions summarized in Item 6 or
otherwise, the Registrant has been advised that, in the opinion of the
Commission, 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-3
5

                                   SIGNATURES

      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 23rd day of
June, 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 PERSONS BY THESE PRESENTS:

      That the undersigned officers and directors of DoubleClick Inc., a
Delaware corporation, do hereby constitute and appoint Kevin J. O'Connor, Chief
Executive Officer and Chairman of the Board of Directors and Stephen R. Collins,
Chief Financial Officer, and each of them, the lawful attorneys-in-fact and
agents with full power and authority to do any and all acts and things and to
execute any and all instruments which said attorneys and agents, and any one of
them, determine 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
that all said attorneys and agents, or any one of them, shall do or cause to be
done by virtue hereof. This Power of Attorney may be signed in several
counterparts.

      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.
SIGNATURE                               TITLE                            DATE
           ---------                               -----                            ----
/s/ Kevin J. O'Connor              Chief Executive Officer and Chairman       June 23, 2000
-----------------------------      of the Board (Principal Executive
Kevin J. O'Connor                  Officer)

/s/ Stephen R. Collins             Chief Financial Officer (Principal         June 23, 2000
-----------------------------      Financial and Accounting Officer)
Stephen R. Collins
II-4
6
SIGNATURE                               TITLE                            DATE
           ---------                               -----                            ----
/s/ Thomas S. Murphy               Director                                   June 23, 2000
-----------------------------
Thomas S. Murphy

/s/ Mark E. Nunnelly               Director                                   June 23, 2000
-----------------------------
Mark E. Nunnelly

                                   Director                                  ____________, _____
-----------------------------
David N. Strohm

                                   Director                                  ____________, _____
-----------------------------
Dwight A. Merriman

/s/ W. Grant Gregory               Director                                   June 23, 2000
-----------------------------
W. Grant Gregory

/s/ Don Peppers                    Director                                   June 23, 2000
-----------------------------
Don Peppers
II-5
7

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

       5          Opinion and consent of Brobeck, Phleger & Harrison LLP.

      23.1        Consent of PricewaterhouseCoopers LLP, Independent Accountants.

      23.2        Consent of KPMG LLP, Independent Accountants

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

      24          Power of Attorney. Reference is made to page II-4 of this
                  Registration Statement.

      99.1        Flashbase, Inc. 1999 Equity Incentive Plan.

      99.2        Form of Assumption Agreement