<PAGE>

                          RETAINED SHAREHOLDER JOINDER

                  By execution of this Retained Shareholder Joinder, the
undersigned agrees to become a party to that certain Shareholders' Agreement
dated as of May 17, 1999, among Greenfield Online, Inc., a Connecticut
corporation, and its shareholders. The undersigned shall have all the rights,
and shall observe all the obligations, applicable to a Retained Shareholder.

                  Upon the effective date of a Sale of the Company, Mr. Nadilo
shall be entitled to designate as Qualifying Retained Shareholder Shares (in
addition to those Retained Shareholder Shares which as of such date constitute
Qualifying Retained Shareholder Shares) such additional Retained Shareholder
Shares equal to, with respect to any Retained Shareholder Shares acquired on any
Retained Shares Acquisition Date, that number of Qualifying Retained Shareholder
Shares that would result in his total number of Qualifying Retained Shareholder
Shares held (including Retained Shareholder Shares which as of such date
constitute Qualifying Retained Shareholder Shares) being equal to 75% of the
number of Retained Shareholder Shares acquired on such Retained Shares
Acquisition Date. This option shall not be exercisable with respect to any
Retained Shareholder Shares in the event that the effective date of the Sale of
the Company occurs on or after the third anniversary of such Retained Shares
Acquisition Date.



Name:  Rudy Nadilo

Address for                                with copies
Notices:                                   to:

1 Riverview Drive                          Jonathan A. Flatow
Norwalk, CT  06850                         Wake, See, Dimes & Bryniczka
                                           27 Imperial Ave.
                                           Westport, CT  06880


                                           Signature:  /s/  Rudy Nadilo
                                                     ---------------------------

                                           Date:       5/17/99
                                                     ---------------------------



<PAGE>


                          RETAINED SHAREHOLDER JOINDER

                  By execution of this Retained Shareholder Joinder, the
undersigned agrees to become a party to that certain Shareholders' Agreement
dated as of May 17, 1999, among Greenfield Online, Inc., a Connecticut
corporation, and its shareholders. The undersigned shall have all the rights,
and shall observe all the obligations, applicable to a Retained Shareholder.

                  Upon the effective date of a Sale of the Company, Mr. Davis
shall be entitled to designate as Qualifying Retained Shareholder Shares (in
addition to those Retained Shareholder Shares which as of such date constitute
Qualifying Retained Shareholder Shares) such additional Retained Shareholder
Shares equal to 50% of the Non-Qualifying Retained Shareholder Shares held by
him on such date.



Name:  Hugh Davis

Address for                                with copies
Notices:                                   to:

PO Box 3028                                Suzanne B. Albani
Westport, CT  06880                        Levett, Rockwood & Sanders
                                           33 Riverside Avenue
                                           Wesport, CT 06881



                                           Signature:     /s/ Hugh Davis
                                                     ---------------------------

                                           Date:          5/17/99
                                                     ---------------------------



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