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                                                                   Exhibit 10.66
                              SALE BONUS AGREEMENT

BY AND AMONG

Greenfield Online, Inc., ("GFOL"),

SRVY Acquisition GmbH ("SRVY"),

Ciao GmbH (the "COMPANY"),

GFOL, SRVY and the Company together herein referred to as the "GFOL-COMPANIES"

AND

Mr. Daniel Keller ("MR. KELLER")

WHEREAS Mr. Keller will be appointed managing director of Ciao GmbH based on an
Employment Agreement dated January 31, 2007;

WHEREAS the shares of the Company are wholly owned by SRVY and the shares of
SRVY are wholly owned by GFOL;

WHEREAS the Company operates the Ciao Comparison Shopping Business ("COMPARISON
SHOPPING BUSINESS"); and

WHEREAS in order to provide Mr. Keller with incentive to maximize the value of
the Comparison Shopping Business for the ultimate benefit of GFOL's
shareholders, the GFOL-Companies are willing to grant him the opportunity to
earn a special sale bonus payable under the conditions defined herein in the
event of the following: (i) the sale of all of the shares in the Company held by
SRVY, (ii) the sale, as defined below, of all or substantially all of the assets
of the Comparison Shopping Business (clauses (i) and (ii) being referred to as
the "SALE"), provided that a definitive document governing the Sale (the "SALE
AGREEMENT") is executed and delivered on or before December 31, 2009 and the
closing of such transaction (the "CLOSING") takes place pursuant to the Sale
Agreement on or prior to September 30, 2010.

NOW IT IS AGREED AS FOLLOWS:

In the event of a Sale to a third party not affiliated with or controlled by
SRVY or GFOL, SRVY and the Company as joint and several debtors (i. e. each of
SRVY and the Company is liable for the full obligation but Mr. Keller is
entitled to one performance only) agree to pay Mr. Keller a special sale bonus
(the "SPECIAL BONUS") in an amount equal to 1.5% of the amount, if any, by which
the value of the Net Sales Proceeds attributable to the Comparison Shopping
Business exceed an amount of U.S. $90,000,000, but in no event shall the Special
Bonus exceed $1,500,000. GFOL shall guarantee the obligations of SRVY and the
Company under this Agreement.

The term "NET SALES PROCEEDS" shall mean the total amount received by either
SRVY or GFOL, as the case may be, as the consideration for the Sale (i. e. the
purchase price minus all direct costs incurred or accrued by GFOL Companies in
connection with the preparation execution and performance of the Sale Agreement,
including, but not limited to, investment banking fees, fairness opinion fees,
attorney's fees, accountant's fees, expert fees, valuation fees, printing,
travel and other expenses), and minus VAT, if any, due on such amount, and minus
cash, cash equivalents and marketable securities

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on the consolidated balance sheet of the entity subject to the Sale on or after
the Closing (whichever is the relevant date for determining the final purchase
price). Any income tax payable by GFOL Companies attributable to the Sale shall
not be deducted in calculating Net Sales Proceeds. In the event that the terms
of the Sale provide for escrows or earnouts, the Net Sales Proceeds shall be
calculated minus these amounts, however, Mr. Keller shall be entitled to a
Special Bonus with respect to such amounts if and to the extent they are
received by SRVY or GFOL prior to the payment of the Deferred Bonus Amount as
defined below.

For purposes of calculating the Net Sales Proceeds, the value of any securities
received by SRVY or GFOL at the time of Closing in connection with a Sale
(whether debt or equity) that are traded on a recognized national stock exchange
or electronic trading market with an active trading market (an "ACTIVE TRADING
MARKET") will be determined on the basis of the closing sale price on such
Active Trading Market on the day prior to the Closing; and the value of
securities that are not traded on an Active Trading Market or other property
that has no established public market will be the fair market value of such
securities or other property on such date as determined by a reputable
investment banker selected by GFOL.

The sale to a third party not affiliated or controlled by SRVY or GFOL of all or
substantially all of the stock or assets of (i) GFOL or (ii) the sale of all or
substantially all of the stock or assets of the Company before the Comparison
Shopping Business has been legally separated from the Online Surveys Business of
the Company, shall be deemed a Sale hereunder, provided, that the Net Sale
Proceeds shall be limited to the proceeds attributable to the Comparison
Shopping Business, which shall be calculated by multiplying the Net Sale
Proceeds (calculated in the manner set forth above) by a fraction, the numerator
of which is the TTM Segment Operating Income of the Comparison Shopping Business
as at the date when the Sale Agreement is executed and delivered, and the
denominator of which is the TTM Segment Operating Income of all Segments for
GFOL as at the date when the Sale Agreement is executed and delivered. For
purposes of the preceding sentence, "TTM SEGMENT OPERATING INCOME" shall be the
Segment Operating Income of the Comparison Shopping business and the GFOL
Company's other operating segments during the twelve months preceding the date
the Sale Agreement is executed and delivered, as reported by GFOL in its
periodic filings with the United States Securities and Exchange Commission,
consistently applied. For example (Dollars in millions):

      -     If the Net Sale Proceeds are $400; and

      -     The total Segment Operating Income for all of GFOL's
            operating segments in the 12 months preceding the date when a
            definitive document governing the Sale is executed and delivered is
            $50; and

      -     The Segment Operating Income for the Comparison Shopping
            Business in the 12 months preceding the date when a definitive
            document governing the Sale is executed and delivered is $20; then

      -     The Net Sale Proceeds attributable to the Comparison Shopping
            Business will be calculated as follows:

               $20 SEGMENT OPERATING INCOME FOR CS  X  $400 (Net Sales Proceeds)
               -----------------------------------
               $50 Segment Operating Income for
               all segments

      -     The Nets Sales Proceeds attributable to the Comparison Shopping
            Business will be $160.

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      -     The Special Bonus shall be paid on the amount of Net Sales Proceeds
            attributable to the Comparison Shopping Business minus $90 ($160 -
            $90 = $70) x 1.5% = $0.105 ($105,000.00)

      The Special Bonus shall be payable in two instalments as follows:

            a)    50% at the Closing;

            b)    50% on December 31, 2009 or one year from the anniversary of
                  the Closing, whichever occurs later (the "DEFERRED BONUS
                  AMOUNT").

Provided, however, that no Deferred Bonus Amount shall be payable if Mr. Keller
is terminated extraordinarily for good cause without the necessity of a prior
notice (au(beta)erordentliche Kuendigung). "Good cause" in this respect shall
have the meaning it has in the context of Mr Keller's Employment Agreement with
the Company., or if he resigns without a Special Reason as such term is defined
in his Employment Contract.

No Special Bonus shall be payable if the Closing takes place following the date
at which Mr Keller is on continuous Gardening Leave (i.e. him being released
from work by the Company under his Employment Contract with the Company) for
more than 60 days.

EFFECTIVE DATE; TERMINATION. This Agreement is effective on and as of January
31, 2007 (the "EFFECTIVE DATE"). This Agreement and the parties obligations
hereunder will terminate on the earlier to occur of the following dates (the
"TERMINATION DATE"): (i) December 31, 2009 provided the Sale Agreement has not
been executed and delivered on or before such date, (ii) September 30, 2010
provided the Closing has not occurred on or prior to such date and the Sale
Agreement was executed and delivered on or prior to December 31, 2009, (iii) the
date on which the Company gives Mr. Keller notice that his employment with the
Company is being terminated for any reason; (iv) the date on which Mr. Keller
gives the Company notice that he is resigning for any reason; or (v) the date of
Mr. Keller's death.

COUNTERPARTS. This Agreement may be executed in any number of separate
counterparts, each of which shall be an original and all of which taken together
shall constitute one and the same instrument. Signatures on any counterpart may
be exchanged among the parties by facsimile or other electronic means and such
counterparts shall be deemed original signatures.

CROSS DEFAULT. Mr. Keller's breach of his Employment Agreement with the Company
shall be deemed a breach of this Agreement, provided that if such breach is
capable of being cured, Mr. Keller fails to cure the breach within 30 days of
receipt from the Company of written notice concerning the breach.

APPLICABLE LAW/ JURISDICTION. THIS AGREEMENT SHALL BE GOVERNED BY, AND CONSTRUED
AND INTERPRETED IN ACCORDANCE WITH, THE LAW OF THE STATE OF DELAWARE, USA
(WITHOUT GIVING EFFECT TO PRINCIPLES OF CONFLICTS OF LAW). The parties hereby
irrevocably consent and agree to subject themselves to the jurisdiction of the
state and federal courts domiciled within the State of Connecticut for the
purposes of resolving any dispute arising under or relating to this Agreement.

                        **** Signature Page Follows ****

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Sale Bonus Agreement Signature Page

Greenfield Online, Inc. (Guarantor Only)        SRVY Acquisition GmbH

By  /s/Jonathan a. Flatow                       By /s/ Jonathan a. Flatow
    ---------------------                          ----------------------
    Title: General Counsel                          Title: Managing Director
    Date: 1/31/07                                   Date: 1/31/07

Ciao GmbH
By SRVY Acquisition its Sole Shareholder

                                                   /s/ Daniel Keller
                                                   -----------------------------
By /s/ Jonathan A. Flatow                          Daniel Keller
   ----------------------                          Date: January 31, 2007
   Title: Managing Director
   Date: 1/31/07