<PAGE>

     As filed with the Securities and Exchange Commission on July 27, 2000

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

                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549
                               ________________

                                    FORM S-8
                          REGISTRATION STATEMENT UNDER
                           THE SECURITIES ACT OF 1933

                               ________________


                          EXCHANGE APPLICATIONS, INC.
             (Exact Name of Registrant as Specified in its Charter)

          DELAWARE                                        04-3338916
(State or Other Jurisdiction                          (I.R.S. Employer
of Incorporation or Organization)                     Identification No.)


                  89 South Street, Boston, Massachusetts 02111
              (Address of Principal Executive Offices) (ZIP Code)

                               ________________

              Exchange Applications Inc. 1998 Stock Incentive Plan
          1999 Customer Analytics, Inc. Stock Option and Purchase Plan
          2000 Customer Analytics Holdings, Inc. Equity Incentive Plan
                           (Full title of the Plans)

                               ________________

                               Andrew J. Frawley
                        Chairman of the Board, President
                          and Chief Executive Officer
                          Exchange Applications, Inc.
                                89 South Street
                                Boston, MA 02111
                    (Name and Address of Agent for Service)

                                 (617) 737-2244
          Telephone Number, Including Area Code, of Agent for Service
                               ________________

                                   Copies to:


                            Neil W. Townsend, Esq.
                               Bingham Dana LLP
                              150 Federal Street
                       Boston, Massachusetts 02110-1726
                                (617) 951-8000

                        CALCULATION OF REGISTRATION FEE

<TABLE>
<CAPTION>
====================================================================================================================
                                                             Proposed          Proposed
                                              Amount         Maximum           Maximum         Amount Of
           Title Of                             To Be     Offering Price      Aggregate       Registration
   Securities To Be Registered                Registered    Per Share     Offering Price (1)      Fee
---------------------------------------------------------------------------------------------------------------------
<S>                                          <C>          <C>             <C>                 <C>
Common Stock,
$.001 par value...................             4,758,959        $23.775       $113,144,250    $29,870.08
=====================================================================================================================
</TABLE>

(1)  Estimated solely for the purpose of computing the registration fee
pursuant to Rule 457(h) under the Securities Act of 1933, as amended, based on
the average of the high and low prices of the Registrant's Common Stock, $.001
par value per share, as reported on the Nasdaq National Market on July 26, 2000.
It is not known how many options will be exercised under the plan or at what
price such shares will be purchased.
<PAGE>

                                    PART II

              INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3.  Incorporation of Documents by Reference.

          The following documents filed by Exchange Applications, Inc. (the
"Registrant") with the Securities and Exchange Commission (the "SEC") are
 ----------                                                     ---
hereby incorporated by reference into this Registration Statement: (1) the
Registrant's Annual Report on Form 10-K for the fiscal year ended December 31,
1999; (2) all reports filed by the Registrant pursuant to Sections 13(a) or
15(d) of the Securities Exchange Act of 1934, as amended (the "Exchange Act"),
                                                               ------------
since the end of the Registrant's 1999 fiscal year; (3) the description of the
Common Stock contained in the Registrant's registration statement on Form 8-A
filed with the SEC on July 23, 1998 under Section 12(g) of the Exchange Act,
including any amendment or report filed for the purpose of updating such
description; and (4) the Registrant's registration statement on Form S-8 filed
with the SEC on July 15, 1999.

          In addition, all documents subsequently filed by the Registrant
pursuant to Sections 13(a), 13(c), 14 and 15(d) of the Exchange Act prior to the
filing of a post-effective amendment that indicate that all securities offered
hereby have been sold or that deregisters all of such 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.

Item 4.   Description of Securities.

          Not applicable.


Item 5.   Interests of Named Experts and Counsel.

          Not applicable.


Item 6.   Indemnification of Directors and Officers.

          Section 145 of the Delaware General Corporation Law empowers a
Delaware corporation to indemnify its officers and directors and certain other
persons to the extent and under the circumstances set forth therein.

          The Amended and Restated Certificate of Incorporation and the Amended
and Restated By-Laws of the Registrant, copies of which are filed herein as
exhibits, provide for indemnification of officers and directors of the
Registrant and certain other persons against liabilities and expenses incurred
by any of them in certain stated proceedings and under certain stated
conditions.

          The Registrant intends to maintain insurance for the benefit of its
directors and officers, insuring such persons against certain liabilities,
including liabilities under the securities laws.

          The above discussion of the Registrant's Amended and Restated
Certificate of Incorporation and Amended and Restated By-Laws and Section 145 of
the Delaware General Corporation Law is not exhaustive, and is qualified in its
entirety by the full text of those documents and law.
<PAGE>

Item 7.   Exemption from Registration Claimed.

          Not applicable.

Item 8.   Exhibits.

          The following exhibits are filed as part of this Registration
          Statement:

  4.1     Form of Amended and Restated Certificate of Incorporation of the
          Registrant (incorporated by reference to Exhibit 3.1 to the
          Registrant's Registration Statement on Form S-1, dated July 22, 1998,
          File No. 333-59613)

  4.2     Form of Amended and Restated By-laws of the Registrant (incorporated
          by reference to Exhibit 3.2 to the Registrant's Registration Statement
          on Form S-1, dated July 22, 1998, File No. 333-59613)

  4.3     Exchange Applications, Inc. 1998 Stock Incentive Plan
          1999 Customer Analytics, Inc. Stock Option and Purchase Plan
          2000 Customer Analytics Holdings, Inc. Equity Incentive Plan
          Form of Customer Analytics Holdings, Inc. Stock Option Agreement

  5.1     Opinion and Consent of Bingham Dana LLP with respect to the legality
          of the shares being registered.

  23.1    Consent of Bingham Dana LLP (included in Exhibit 5.1).

  23.2    Consent of Arthur Andersen LLP.

  24      Power of Attorney (included in signature page).


Item 9.   Undertakings.

          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 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;

(2)       That, for the purpose of determining any liability under the
Securities 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;

(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
offering;

(4)       That, for purposes of determining any liability under the Securities
Act of 1933, as amended, each filing of the Registrant's annual report pursuant
to Sections 13(a) or 15(d) of the Exchange Act (and, where applicable, each
filing of an employee benefit plan's annual report pursuant to Section 15(d) of
the Exchange Act) that is incorporated by reference in 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; and
<PAGE>

(5)       Insofar as indemnification for liabilities arising under the
Securities Act may be permitted to directors, officers and controlling persons
of the Registrant pursuant to the foregoing provisions, or otherwise, the
Registrant has been advised that in the opinion of the SEC such indemnification
is against public policy as expressed in the Securities 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 Securities Act and will be governed by the final
adjudication of such issue.
<PAGE>

                                   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 Boston, Commonwealth of Massachusetts, on this
27th day of July, 2000.

                                  EXCHANGE APPLICATIONS, INC.


                                  By: /s/ Andrew J. Frawley
                                     -----------------------------------
                                       Andrew J. Frawley
                                       Chairman of the Board, President
                                       and Chief Executive Officer

                               POWER OF ATTORNEY

     KNOW ALL MEN BY THESE PRESENTS, that each person whose signature appears
below hereby appoints Andrew J. Frawley and John G. O'Brien and each of them
severally, acting alone and without the other, his true and lawful attorney-in-
fact with the authority to execute in the name of each such person, and to file
with the Securities and Exchange Commission, together with any exhibits thereto
and other documents therewith, any and all amendments (including without
limitation post-effective amendments) to this Registration Statement on Form S-8
necessary or advisable to enable the Registrant to comply with the Securities
Act of 1933, as amended, and any rules, regulations, and requirements of the
Securities and Exchange Commission in respect thereof, which amendments may make
such other changes in the Registration Statement as the aforesaid attorney-in-
fact executing the same deems appropriate.

     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/  Andrew J. Frawley        Chairman of the Board, President,       7/27/2000
---------------------------
     Andrew J. Frawley        Chief Executive Officer and Director
                              (Principal Executive Officer)

/s/  Dean F. Goodermote                 Director                      7/27/2000
---------------------------
Dean F. Goodermote

  /s/  Ramanan Raghavendran             Director                      7/27/2000
---------------------------
Ramanan Raghavendran

  /s/  William Bryant                   Director                      7/27/2000
--------------------------
William Bryant

  /s/  John G. O'Brien               Vice President                   7/27/2000
--------------------------       Chief Financial Officer,
John G. O'Brien              Treasurer and Secretary (Principal
                             Financial and Accounting Officer)
<PAGE>

                               INDEX TO EXHIBITS


Exhibit
-------
Number                   Description
------                   -----------

  4.1     Form of Amended and Restated Certificate of Incorporation of the
          Registrant (incorporated by reference to Exhibit 3.1 to the
          Registrant's Registration Statement on Form S-1, dated July 22, 1998,
          File No. 333-59613)

  4.2     Form of Amended and Restated By-laws of the Registrant (incorporated
          by reference to Exhibit 3.2 to the Registrant's Registration Statement
          on Form S-1, dated July 22, 1998, File No. 333-59613)

  4.3     Exchange Applications, Inc. 1998 Stock Incentive Plan
          1999 Customer Analytics, Inc. Stock Option and Purchase Plan
          2000 Customer Analytics Holdings, Inc. Equity Incentive Plan
          Form of Customer Analytics Holdings, Inc. Stock Option Agreement

  5.1     Opinion and Consent of Bingham Dana LLP with respect to the legality
          of the shares being registered.

 23.1     Consent of Bingham Dana LLP (included in Exhibit 5.1).

 23.2     Consent of Arthur Andersen LLP.

   24     Power of Attorney (included in signature page to Registration
          Statement).
[{"type": "S-8", "sequence": "1", "filename": "0001.txt", "description": "FORM S-8", "secsgml_size_bytes": 14839}]
{"company-data": {"conformed-name": "EXCHANGE APPLICATIONS INC", "cik": "0001065857", "assigned-sic": "7373", "irs-number": "043338916", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-42344", "film-number": "679894"}, "business-address": {"street1": "89 SOUTH STREET", "city": "BOSTON", "state": "MA", "zip": "02111", "phone": "6177372244"}, "mail-address": {"street1": "89 SOUTH STREET", "city": "BOSYON", "state": "MA", "zip": "02111"}}
As filed with the Securities and Exchange Commission on July 27, 2000

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

                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549
                               ________________

                                    FORM S-8
                          REGISTRATION STATEMENT UNDER
                           THE SECURITIES ACT OF 1933

                               ________________

                          EXCHANGE APPLICATIONS, INC.
             (Exact Name of Registrant as Specified in its Charter)

          DELAWARE                                        04-3338916
(State or Other Jurisdiction                          (I.R.S. Employer
of Incorporation or Organization)                     Identification No.)

                  89 South Street, Boston, Massachusetts 02111
              (Address of Principal Executive Offices) (ZIP Code)

                               ________________

              Exchange Applications Inc. 1998 Stock Incentive Plan
          1999 Customer Analytics, Inc. Stock Option and Purchase Plan
          2000 Customer Analytics Holdings, Inc. Equity Incentive Plan
                           (Full title of the Plans)

                               ________________

                               Andrew J. Frawley
                        Chairman of the Board, President
                          and Chief Executive Officer
                          Exchange Applications, Inc.
                                89 South Street
                                Boston, MA 02111
                    (Name and Address of Agent for Service)

                                 (617) 737-2244
          Telephone Number, Including Area Code, of Agent for Service
                               ________________

                                   Copies to:

                            Neil W. Townsend, Esq.
                               Bingham Dana LLP
                              150 Federal Street
                       Boston, Massachusetts 02110-1726
                                (617) 951-8000

                        CALCULATION OF REGISTRATION FEE
====================================================================================================================
                                                             Proposed          Proposed
                                              Amount         Maximum           Maximum         Amount Of
           Title Of                             To Be     Offering Price      Aggregate       Registration
   Securities To Be Registered                Registered    Per Share     Offering Price (1)      Fee
---------------------------------------------------------------------------------------------------------------------
Common Stock,
$.001 par value...................             4,758,959        $23.775       $113,144,250    $29,870.08
=====================================================================================================================
(1)  Estimated solely for the purpose of computing the registration fee
pursuant to Rule 457(h) under the Securities Act of 1933, as amended, based on
the average of the high and low prices of the Registrant's Common Stock, $.001
par value per share, as reported on the Nasdaq National Market on July 26, 2000.
It is not known how many options will be exercised under the plan or at what
price such shares will be purchased.
PART II

              INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3.  Incorporation of Documents by Reference.

          The following documents filed by Exchange Applications, Inc. (the
"Registrant") with the Securities and Exchange Commission (the "SEC") are
 ----------                                                     ---
hereby incorporated by reference into this Registration Statement: (1) the
Registrant's Annual Report on Form 10-K for the fiscal year ended December 31,
1999; (2) all reports filed by the Registrant pursuant to Sections 13(a) or
15(d) of the Securities Exchange Act of 1934, as amended (the "Exchange Act"),
                                                               ------------
since the end of the Registrant's 1999 fiscal year; (3) the description of the
Common Stock contained in the Registrant's registration statement on Form 8-A
filed with the SEC on July 23, 1998 under Section 12(g) of the Exchange Act,
including any amendment or report filed for the purpose of updating such
description; and (4) the Registrant's registration statement on Form S-8 filed
with the SEC on July 15, 1999.

          In addition, all documents subsequently filed by the Registrant
pursuant to Sections 13(a), 13(c), 14 and 15(d) of the Exchange Act prior to the
filing of a post-effective amendment that indicate that all securities offered
hereby have been sold or that deregisters all of such 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.

Item 4.   Description of Securities.

          Not applicable.

Item 5.   Interests of Named Experts and Counsel.

          Not applicable.

Item 6.   Indemnification of Directors and Officers.

          Section 145 of the Delaware General Corporation Law empowers a
Delaware corporation to indemnify its officers and directors and certain other
persons to the extent and under the circumstances set forth therein.

          The Amended and Restated Certificate of Incorporation and the Amended
and Restated By-Laws of the Registrant, copies of which are filed herein as
exhibits, provide for indemnification of officers and directors of the
Registrant and certain other persons against liabilities and expenses incurred
by any of them in certain stated proceedings and under certain stated
conditions.

          The Registrant intends to maintain insurance for the benefit of its
directors and officers, insuring such persons against certain liabilities,
including liabilities under the securities laws.

          The above discussion of the Registrant's Amended and Restated
Certificate of Incorporation and Amended and Restated By-Laws and Section 145 of
the Delaware General Corporation Law is not exhaustive, and is qualified in its
entirety by the full text of those documents and law.
Item 7.   Exemption from Registration Claimed.

          Not applicable.

Item 8.   Exhibits.

          The following exhibits are filed as part of this Registration
          Statement:

  4.1     Form of Amended and Restated Certificate of Incorporation of the
          Registrant (incorporated by reference to Exhibit 3.1 to the
          Registrant's Registration Statement on Form S-1, dated July 22, 1998,
          File No. 333-59613)

  4.2     Form of Amended and Restated By-laws of the Registrant (incorporated
          by reference to Exhibit 3.2 to the Registrant's Registration Statement
          on Form S-1, dated July 22, 1998, File No. 333-59613)

  4.3     Exchange Applications, Inc. 1998 Stock Incentive Plan
          1999 Customer Analytics, Inc. Stock Option and Purchase Plan
          2000 Customer Analytics Holdings, Inc. Equity Incentive Plan
          Form of Customer Analytics Holdings, Inc. Stock Option Agreement

  5.1     Opinion and Consent of Bingham Dana LLP with respect to the legality
          of the shares being registered.

  23.1    Consent of Bingham Dana LLP (included in Exhibit 5.1).

  23.2    Consent of Arthur Andersen LLP.

  24      Power of Attorney (included in signature page).

Item 9.   Undertakings.

          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 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;

(2)       That, for the purpose of determining any liability under the
Securities 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;

(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
offering;

(4)       That, for purposes of determining any liability under the Securities
Act of 1933, as amended, each filing of the Registrant's annual report pursuant
to Sections 13(a) or 15(d) of the Exchange Act (and, where applicable, each
filing of an employee benefit plan's annual report pursuant to Section 15(d) of
the Exchange Act) that is incorporated by reference in 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; and
(5)       Insofar as indemnification for liabilities arising under the
Securities Act may be permitted to directors, officers and controlling persons
of the Registrant pursuant to the foregoing provisions, or otherwise, the
Registrant has been advised that in the opinion of the SEC such indemnification
is against public policy as expressed in the Securities 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 Securities Act and will be governed by the final
adjudication of such issue.
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 Boston, Commonwealth of Massachusetts, on this
27th day of July, 2000.

                                  EXCHANGE APPLICATIONS, INC.

                                  By: /s/ Andrew J. Frawley
                                     -----------------------------------
                                       Andrew J. Frawley
                                       Chairman of the Board, President
                                       and Chief Executive Officer

                               POWER OF ATTORNEY

     KNOW ALL MEN BY THESE PRESENTS, that each person whose signature appears
below hereby appoints Andrew J. Frawley and John G. O'Brien and each of them
severally, acting alone and without the other, his true and lawful attorney-in-
fact with the authority to execute in the name of each such person, and to file
with the Securities and Exchange Commission, together with any exhibits thereto
and other documents therewith, any and all amendments (including without
limitation post-effective amendments) to this Registration Statement on Form S-8
necessary or advisable to enable the Registrant to comply with the Securities
Act of 1933, as amended, and any rules, regulations, and requirements of the
Securities and Exchange Commission in respect thereof, which amendments may make
such other changes in the Registration Statement as the aforesaid attorney-in-
fact executing the same deems appropriate.

     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/  Andrew J. Frawley        Chairman of the Board, President,       7/27/2000
---------------------------
     Andrew J. Frawley        Chief Executive Officer and Director
                              (Principal Executive Officer)

/s/  Dean F. Goodermote                 Director                      7/27/2000
---------------------------
Dean F. Goodermote

  /s/  Ramanan Raghavendran             Director                      7/27/2000
---------------------------
Ramanan Raghavendran

  /s/  William Bryant                   Director                      7/27/2000
--------------------------
William Bryant

  /s/  John G. O'Brien               Vice President                   7/27/2000
--------------------------       Chief Financial Officer,
John G. O'Brien              Treasurer and Secretary (Principal
                             Financial and Accounting Officer)
INDEX TO EXHIBITS

Exhibit
-------
Number                   Description
------                   -----------

  4.1     Form of Amended and Restated Certificate of Incorporation of the
          Registrant (incorporated by reference to Exhibit 3.1 to the
          Registrant's Registration Statement on Form S-1, dated July 22, 1998,
          File No. 333-59613)

  4.2     Form of Amended and Restated By-laws of the Registrant (incorporated
          by reference to Exhibit 3.2 to the Registrant's Registration Statement
          on Form S-1, dated July 22, 1998, File No. 333-59613)

  4.3     Exchange Applications, Inc. 1998 Stock Incentive Plan
          1999 Customer Analytics, Inc. Stock Option and Purchase Plan
          2000 Customer Analytics Holdings, Inc. Equity Incentive Plan
          Form of Customer Analytics Holdings, Inc. Stock Option Agreement

  5.1     Opinion and Consent of Bingham Dana LLP with respect to the legality
          of the shares being registered.

 23.1     Consent of Bingham Dana LLP (included in Exhibit 5.1).

 23.2     Consent of Arthur Andersen LLP.

   24     Power of Attorney (included in signature page to Registration
          Statement).