FILING AGREEMENT BETWEEN BOSTON PIPES, LLC AND JACOB GOLDFIELD The undersigned hereby agree that the Schedule 13D with respect to the Common Stock, $.001 par value, of Exchange Applications, Inc. dated of even date herewith is and shall be filed on...

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                                                                       EXHIBIT 7


                                FILING AGREEMENT
                                     BETWEEN
                                BOSTON PIPES, LLC
                                       AND
                               XXXXX XXXXXXXXX


        The undersigned hereby agree that the Schedule 13D with respect to the
Common Stock, $.001 par value, of Exchange Applications, Inc. dated of even date
herewith is and shall be filed on behalf of both of us pursuant to and in
accordance with the provisions of Rule 13d-1(k)(1) under the Securities Exchange
Act of 1934, as amended.

Dated:  September 17, 2001

                                     BOSTON PIPES, LLC



                                     By: /s/ Xxxxx Xxxxxxxxx
                                         -------------------------
                                         Xxxxx Xxxxxxxxx
                                         Managing Member








                                         /s/ Xxxxx  Xxxxxxxxx
                                         -------------------------
                                         Xxxxx Xxxxxxxxx