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                                                                     EXHIBIT 4.3

                          REGISTRATION RIGHTS AGREEMENT

         THIS REGISTRATION RIGHTS AGREEMENT is entered into as of August 9,
2001, by and between Silicon Valley Bank ("Purchaser") and Greenfield Online,
Inc., a Delaware corporation (the "Company").

                                    RECITALS

         A. Concurrently with the execution of this Agreement, Purchaser is
acquiring from the Company a Warrant to Purchase Stock (the "Warrants") pursuant
to which Purchaser has rights to acquire from the Company the Shares (as defined
in the Warrant), which Shares when issued shall be shares of the Company's
common stock, $0.0001 par value per share ("Common Stock").

         B. By this Agreement, Purchaser and the Company desire to set forth the
registration rights of the Shares all as provided herein.

            NOW, THEREFORE, in consideration of the premises and the mutual
promises, covenants and conditions hereinafter set forth, the parties hereto
mutually agree as follows:

         1. Registration Rights. The Company covenants and agrees as follows:

            1.1 Definitions. For purposes of this Section 1:


               (a) The term "register," "registered," and "registration" refer
to a registration effected by preparing and filing a registration statement or
similar document in compliance with the Securities Act of 1933, as amended, and
the rules and regulations thereunder (the "Securities Act"), and the declaration
or ordering of effectiveness of such registration statement or document;

               (b) The term "Registrable Securities" means (i) the Shares, at
any time when the Shares are shares of Common Stock, and (ii) any Common Stock
or other securities of the Company issued as (or issuable upon the conversion or
exercise of any warrant, right or other security which is issued as) a dividend
or other distribution with respect to, or in exchange for or in replacement of,
the Shares. Shares shall cease to be Registrable Securities when they are
eligible for sale in any three-month period pursuant to Rule 144(k) issued under
the Securities Act.

               (c) The terms "Holder" or "Holders" means Purchaser, so long as
it shall hold or have rights to acquire Registrable Securities, and its
qualifying transferees under subsection 1.9 hereof who hold or have rights to
acquire Registrable Securities.

               (d) The term "SEC" means the Securities and Exchange Commission.

               (e) The terms "Form S-1," "Form S-3" etc. shall mean those forms
with such designations as are required by the SEC and any successor or
replacement forms adopted by the SEC.

            1.2 Company Registration.

               (a) Registration. For a period of seven (7) years after the
Shares are so acquired, if the Company shall determine to register any of its
securities, for its own account or the account of any of its shareholders, other
than a registration on Form S-8 or on Form S-4

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relating solely to an SEC Rule 145 transaction or on Form S-4 relating solely to
a merger, recapitalization, consolidation, acquisition or similar transaction
(or pursuant to successor forms promulgated under the act), the Company will:

                  (i) promptly give to each Holder written notice thereof (which
shall include a list of the jurisdictions in which the Company intends to
attempt to qualify such securities under the applicable blue sky or other state
securities laws); and

                  (ii) include in such registration (and qualifications), and in
any underwriting involved therein, all the Registrable Securities specified in a
written request or requests, made within 30 days after receipt of such written
notice from the Company, by any Holder or Holders, except as set forth in
subsection 1.2(c) below.

               (b) Underwriting. If the registration of which the Company gives
notice is for a registered public offering involving a firm-commitment
underwriting, the Company shall so advise the Holders as a part of the written
notice given pursuant to subsection 1.2(a)(i). In such event the right of any
Holder to registration pursuant to this subsection 1.2 shall be conditioned upon
such Holder's participation in such underwriting and the inclusion of such
Holder's Registrable Securities in the underwriting to the extent provided
herein. All Holders proposing to distribute their securities through such
underwriting shall (together with the Company and the other shareholders
distributing their securities through such underwriting) enter into an
underwriting agreement in customary form (and not inconsistent with the terms
hereof) with the underwriter or underwriters selected for such underwriting by
the Company.

               (c) Underwriter Cutback. In the case of any registration of
Common Stock by the Company in a firm-commitment underwriting, if the managing
underwriters give written advice to the Company that marketing factors require a
limitation on all or any part of the number of shares of Common Stock (or other
securities convertible into or exercisable or exchangeable for Common Stock) to
be offered and sold by stockholders of the Company in such offering, there shall
be included in the offering: (i) first, all securities proposed by Company to be
sold for its account; (ii) second, that number of shares of Common Stock, if
any, requested to be included in such registration statement by stockholders of
the Company holding registration rights pursuant to that certain Registration
Rights Agreement of the Company dated May 17, 1999, as amended August 23, 2000,
and March 1, 2001, and (iii) third, that number of shares of Common Stock, if
any requested to be included in such registration statement by Holders and by
other stockholders of the Company having contractual rights to include shares in
such registration, on a pro rata basis based upon the number of shares of Common
Stock each Holder and each such other stockholder beneficially owns, except that
where such a registration is initiated by another shareholder having contractual
registration rights, such shareholder shall be considered before Holder.

               (d) "Stand-Off" Agreement. Each Holder of Registrable Securities,
if requested by the Company and the managing underwriter of an offering by the
Company of Common Stock pursuant to a registration statement, shall be
prohibited from selling, pledging, or otherwise transferring any interest in any
Registrable Securities or other securities of the Company held by such Holder of
Registrable Securities for a specified period of time (not to exceed 180 days)
following the effective date of such registration statement; provided, that:

         i.       such prohibition shall only apply to the first registration
                  statement covering Common Stock to be sold by or on behalf of
                  the Company to the public in an underwritten offering; and
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         ii.      all officers and directors of the Company, all holders of 5%
                  or more of the Company's equity securities and all selling
                  stockholders in such offering shall be subject to a similar
                  prohibition.

            1.3 Registration on Form S-3. If at any time (i) the Holder of
Registrable Securities requests in writing that the Company file a registration
statement on Form S-3 or any successor thereto for a public offering of all or
any portion of the shares of Registrable Securities held by the requesting
Holder, (ii) the aggregate price to the public of such offering would reasonably
be expected to exceed $750,000, and (iii) the Company is a registrant entitled
to use Form S-3 or any successor thereto to register such shares, then the
Company shall use its best efforts to register under the Securities Act on Form
S-3 or any successor thereto, for public sale in accordance with the method of
disposition specified in such notice, the number of shares of Registrable
Securities specified in such notice. Whenever the Company is required by this
Section 1.3 to use its best efforts to effect the registration of Registrable
Securities, each of the procedures and requirements of Section 1.5(d) shall
apply to such registration; provided, however, that the Company shall not be
obligated to register Registrable Securities under this Section 1.3 on more than
two occasions or on more than one occasion in any six-month period.

            Notwithstanding anything to the contrary in this Agreement, the
Company may delay the filing of a registration statement on Form S-3 if: (i) in
the good faith and reasonable judgment of the Board of Directors of the Company,
such registration would be seriously detrimental to the Company, and the Board
of Directors concludes, as a result, that it is essential to defer the filing of
such registration statement at such time, and (ii) the Company shall furnish to
the Holders a certificate signed by the President of the Company stating that in
the good faith judgment of the Board of Directors, it would be seriously
detrimental to the Company for such registration statement to be filed in the
near future and that it is, therefore, essential to defer the filing of such
registration statement.

         Upon receipt of any notice (a "Suspension Notice") from the Company of
the happening of any event which makes any statement made in the S-3 or related
prospectus untrue or which requires the making of any changes in such Form S-3
or prospectus so that they will not contain any untrue statement of a material
fact or omit to state any material fact required to be stated therein or
necessary to make the statements therein in light of the circumstances under
which they were made not misleading, each Holder shall forthwith discontinue
disposition of shares pursuant to such Form S-3 until such Holder's receipt of
the copies of the supplemented or amended prospectus (which the Company shall
use commercially reasonable efforts to prepare and distribute promptly) or until
it is advised in writing (the "Advice" ) by the Company that the use of the
prospectus may be resumed, and has received copies of any additional or
supplemental filings which are incorporated by reference in the prospectus.

            1.4 Expenses of Registration. All expenses incurred in connection
with any registration, qualification or compliance pursuant to this Section 1
including without limitation, all registration, filing and qualification fees,
printing expenses, underwriting fees, discounts and commissions, fees and
disbursements of counsel for the Company and expenses of any special audits
incidental to or required by such registration, shall be borne by the Company,
provided, however, that the Holders shall pay the fees and expenses of their
respective counsel and accountants and underwriting discounts and commissions
and transfer taxes in respect of any such registration or compliance being
registered. All expenses of any registered offering not otherwise borne by the
Company will be borne pro rata among the Holders, any other shareholders of the
Company participating in such offering and the Company.
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            1.5 Registration Procedures. In the case of each registration,
qualification or compliance effected by the Company pursuant to this
Registration Rights Agreement, the Company will keep each Holder participating
therein advised in writing as to the initiation of each registration,
qualification and compliance and as to the completion thereof. At its expense
the Company will:

               (a) Prepare and file with the SEC a registration statement with
respect to such Registrable Securities and use its best efforts to cause such
registration statement to become effective, and, in the case of a registration
under Section 1.3, upon the request of the Holders of a majority of the
Registrable Securities registered thereunder, keep such registration statement
effective for up to 90 days (the "Effective Period").

               (b) Prepare and file with the SEC such amendments and supplements
to such registration statement and the prospectus used in connection with such
registration statement as may be necessary to comply with the provisions of the
Securities Act with respect to the disposition of all securities covered by such
registration statement.

               (c) Furnish to the Holders such numbers of copies of a
prospectus, including a preliminary prospectus, in conformity with the
requirements of the Securities Act, and such other documents as they may
reasonably request in order to facilitate the disposition of Registrable
Securities owned by them.

               (d) If required by law, use its best efforts to register and
qualify the securities covered by such registration statement under such other
securities or Blue Sky laws of such jurisdictions as shall be reasonably
requested by the Holders, provided that the Company shall not be required in
connection therewith or as a condition thereto to qualify to do business or to
file a general consent to service of process in any such states or
jurisdictions.

               (e) In the event of any underwritten public offering, enter into
and perform its obligations under an underwriting agreement, in usual and
customary form, with the managing underwriter of such offering. Each Holder
participating in such underwriting shall also enter into and perform its
obligations under such an agreement provided that all other shareholders of the
Company participating in such offering do the same.

               (f) Notify each Holder of Registrable Securities covered by such
registration statement at any time when a prospectus relating thereto is
required to be delivered under the Securities Act or the happening of any event
as a result of which the prospectus included in such registration statement, as
then in effect, includes an untrue statement of a material fact or omits to
state a material fact required to be stated therein or necessary to make the
statements therein not misleading in the light of the circumstances then
existing.

            1.6 Indemnification.

               (a) The Company will indemnify each Holder of Registrable
Securities and each of its officers, directors and partners, and each person
controlling such Holder within the meaning of Section 15 of the Securities Act
("controlling person"), with respect to which registration, qualification or
compliance of Registrable Securities has been effected pursuant to this
Registration Rights Agreement, against all claims, losses, expenses, damages and
liabilities (or actions in respect thereto) arising out of or based on any
untrue statement (or alleged untrue statement) of a material fact contained in
any prospectus, offering circular or other document (including any related
registration statement, notification or the like) incident to any

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such registration, qualification or compliance, or based on any omission (or
alleged omission) to state therein a material fact required to be stated therein
or necessary to make the statement therein not misleading, or any violation or
alleged violation by the Company of the Securities Act, the Securities Exchange
Act of 1934, as amended, and the rules and regulations thereunder ("Exchange
Act") or any state securities law applicable to the Company or any rule or
regulation promulgated any such state law and relating to action or inaction
required of the Company in connection with any such registration, qualification
or compliance, and will reimburse each such Holder, each of its officers,
directors and partners, and each person controlling such Holder, within a
reasonable amount of time after incurred for any reasonable legal and any other
expenses incurred in connection with investigating, defending or settling any
such claim, loss, damage, liability or action; provided, however, that the
indemnity agreement contained in this subsection 1.6(a) shall not apply to
amounts paid in settlement of any such claim, loss, damage, liability, or action
if such settlement is effected without the consent of the Company (which consent
shall not be unreasonably withheld or delayed); and provided further, that the
Company will not be liable in any such case to the extent that any such claim,
loss, damage or liability arises out of or is based on any untrue statement or
omission made in reliance upon and conformity with written information furnished
to the Company by an instrument duly executed by or on behalf of such Holder
specifically for use therein, and provided further that the indemnity agreement
contained in this subsection 1.6(a) shall not apply to the extent that any such
claim, loss, damage or liability arises out of or is based on the Holder's use
of a prospectus after the Company has notified the Holder under Section 1.4(f).

            (b) Each Holder will, if Registrable Securities held by or issuable
to such Holder are included in the securities as to which such registration,
qualification or compliance is being effected, indemnify the Company, each of
its directors, officers and controlling persons, each underwriter, if any, of
the Company's securities covered by such a registration statement, and each
controlling person of such underwriter, and each other Holder, each of its
officers, directors, partners and controlling persons, against all claims,
losses, expenses, damages and liabilities (or actions in respect thereof)
arising out of or based on any untrue statement (or alleged untrue statement) of
a material fact contained in any such registration statement, prospectus,
offering circular or other document, or any omission (or alleged omission) to
state therein a material fact required to be stated therein or necessary to make
the statements therein not misleading, and will reimburse the Company, such
Holders, such directors, officers, partners, persons or underwriters for any
reasonable legal or any other expenses incurred in connection with
investigating, defending or settling any such claim, loss, damage, liability or
action, in each case to the extent, but only to the extent, that such untrue
statement (or alleged untrue statement) or omission (or alleged omission) is
made in such registration statement, prospectus, offering circular or other
document in reliance upon and in conformity with written information furnished
to the Company by an instrument duly executed by or on behalf of such Holder
specifically for use therein; provided, however, that the indemnity agreement
contained in this subsection 1.6(b) shall not apply to amounts paid in
settlement of any such claim, loss, damage, liability or action if such
settlement is effected without the consent of the Holder, (which consent shall
not be unreasonably withheld or delayed); and provided further, that the total
amount for which any Holder shall be liable under this subsection 1.6(b) shall
not in any event exceed the aggregate net proceeds received by such Holder from
the sale of Registrable Securities held by such Holder in such registration.

            (c) Each party entitled to indemnification under this subsection 1.6
(the "Indemnified Party") shall give notice to the party required to provide
indemnification (the "Indemnifying Party") promptly after such Indemnified Party
has actual knowledge of any claim as to which indemnity may be sought, and shall
permit the Indemnifying Party to assume the

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defense of any such claim or any litigation resulting therefrom; provided that
counsel for the Indemnifying Party, who shall conduct the defense of such claim
or litigation, shall be approved by the Indemnified Party (whose approval shall
not be unreasonably withheld), and the Indemnified Party may participate in such
defense at such party's expense; and provided further, that the failure of any
Indemnified Party to give notice as provided herein shall not relieve the
Indemnifying Party of its obligations hereunder, unless such failure resulted in
prejudice to the Indemnifying Party; and provided further, that an Indemnified
Party (together with all other Indemnified Parties which may be represented
without conflict by one counsel) shall have the right to retain one separate
counsel, with the fees and expenses to be paid by the Indemnifying Party, if
representation of such Indemnified Party by the counsel retained by the
Indemnifying Party would in the unqualified written opinion of counsel to the
Holder, be inappropriate due to actual or potential differing interests between
such Indemnified Party and any other party represented by such counsel in such
proceeding. No Indemnifying Party, in the defense of any such claim or
litigation, shall, except with the consent of each Indemnified Party, consent to
entry of any judgment or enter into any settlement which does not include as an
unconditional term thereof the giving by the claimant or plaintiff to such
Indemnified Party of a release from all liability in respect to such claim or
litigation.

            (d) In order to provide for just and equitable contribution in
circumstances in which the indemnification provided for in this Section 1.6 is
due in accordance with its terms but for any reason is judicially determined to
be unenforceable against the Indemnifying Party or otherwise unavailable to the
Indemnified Party in respect to any losses, claims, damages and liabilities
referred to herein, then the Indemnifying Party shall, in lieu of indemnifying
such Indemnified Party, contribute to the amount paid or payable by such
Indemnified party as a result of such losses, claims, damages or liabilities to
which such party may be subject in such proportion as is appropriate to reflect
the relative fault of the Company, on the one hand, and the selling Holders, on
the other hand, in connection with the statements or omissions which resulted in
such losses, claims, damages or liabilities, as well as any other relevant
equitable considerations. The relative fault of the Company and such selling
Holders shall be determined by reference to, among other things, whether the
untrue or alleged untrue statement, or omission or alleged omission, of material
fact related to the information supplied by the Company or such selling Holders
and the parties' relative intent, knowledge, access to information and
opportunity to correct or prevent such statement or omission. The Company and
Holders agree that it would not be just and equitable if contribution pursuant
to this Section 1.6(d) were determined by pro rata allocation or any other
method of allocation which does not take account of the equitable considerations
referred to above. Notwithstanding the provisions of this Section 1.6(d), (i) in
no case shall any Holder be liable or responsible for any amount in excess of
the net proceeds received by such Holder from the sale of Registrable Securities
pursuant to such registration; and (ii) no person adjudged guilty of fraudulent
misrepresentation (within the meaning of Section 11(f) of the Securities Act)
shall be entitled to contribution from any person who was not adjudged guilty of
such fraudulent misrepresentation. Any party entitled to contribution shall,
promptly after receipt of notice of commencement of any action, suit or
proceeding against such party in respect of which a claim for contribution may
be made against another party or parties under this Section 1.6(d), notify such
party or parties from whom contribution may be sought, but the omission so to
notify such party or parties from whom contribution may be sought shall not, in
the absence of actual prejudice to such party or parties, relieve it or them
from such contribution obligation. No party shall be liable for contribution
with respect to any action, suit, proceeding or claim settled without its
written consent.

            1.7 Information by Holder. Any Holder or Holders of Registrable
Securities included in any registration shall promptly furnish to the Company
such information regarding

<PAGE>

such Holder or Holders and the distribution proposed by such Holder or Holders
as the Company may request in writing and as shall be required in connection
with any registration, qualification or compliance referred to herein.

            1.8 Rule 144 Reporting and Form S-3. With a view to making available
to Holders the benefits of certain rules and regulations of the SEC which may
permit the sale of the Registrable Securities to the public without registration
or pursuant to a registration on Form S-3, the Company agrees for a two (2) year
period after the Shares are issued to use commercially reasonable efforts to:

               (a) make and keep public information available, as those terms
are understood and defined in SEC Rule 144, after 90 days after the effective
date of the first registration filed by the Company for an offering of its
securities to the general public;

               (b) take such commercially reasonable action as is necessary to
enable the Holders to utilize Form S-3 for the sale of their Registrable
Securities, such action to be taken as soon as practicable after the end of the
fiscal year in which the first registration statement filed by the Company for
the offering of its securities to the general public is declared effective;

               (c) file with the SEC in a timely manner all reports and other
documents required of the Company under the Securities Act and the Exchange Act
(at any time after it has become subject to such reporting requirements); and

               (d) so long as a Holder owns any Registrable Securities, to
furnish to such Holder forthwith upon request a written statement by the Company
as to its compliance with the reporting requirements of said Rule 144 (at any
time after 90 days after the effective date of the first registration statement
filed by the Company for an offering of its securities to the general public),
and of the Securities Act and the Exchange Act (at any time after it has become
subject to such reporting requirements), or that it qualify as a registrant
whose securities may be resold pursuant to S-3 (at any time after it so
qualifies), and such reports and documents as the Holder may reasonably request
in order to document its compliance with any rule or regulation of the SEC
allowing the Holder to sell any such securities without registration or pursuant
to such form.

            1.9 Transfer of Registration Rights. Holders' rights to cause the
Company to register their securities and keep information available, granted to
them by the Company under subsections 1.2, 1.3 and 1.8 may be assigned to a
transferee or assignee of 200,000 or more of Holder's Registrable Securities not
sold to the public, provided, that the Company is given written notice by such
Holder at the time of or within a reasonable time after said transfer, stating
the name and address of said transferee or assignee and identifying the
securities with respect to which such registration rights are being assigned.

         2. General.

            2.1 Waivers and Amendments. With the written consent of the record
or beneficial holders of at least a majority of the Registrable Securities, the
obligations of the Company and the rights of the Holders of the Registrable
Securities under this agreement may be waived (either generally or in a
particular instance, either retroactively or prospectively, and either for a
specified period of time or indefinitely), and with the same consent the
Company, when authorized by resolution of its Board of Directors, may enter into
a supplementary agreement for the purpose of adding any provisions to or
changing in any manner or eliminating

<PAGE>

any of the provisions of this Agreement; provided, however, that no such
modification, amendment or waiver shall reduce the aforesaid percentage of
Registrable Securities without the consent of all of the Holders of the
Registrable Securities. Upon the effectuation of each such waiver, consent,
agreement of amendment or modification, the Company shall promptly give written
notice thereof to the record holders of the Registrable Securities who have not
previously consented thereto in writing. This Agreement or any provision hereof
may be changed, waived, discharged or terminated only by a statement in writing
signed by the party against which enforcement of the change, waiver, discharge
or termination is sought, except to the extent provided in this subsection 2.1.

            2.2 Governing Law. This Agreement shall be governed in all respects
by the laws of the State of Delaware as such laws are applied to agreements
between Delaware residents entered into and to be performed entirely within
Delaware.

            2.3 Successors and Assigns. Except as otherwise expressly provided
herein, the provisions hereof shall inure to the benefit of, and be binding
upon, the successors, assigns, heirs, executors and administrators of the
parties hereto.

            2.4 Entire Agreement. Except as set forth below, this Agreement and
the other documents delivered pursuant hereto constitute the full and entire
understanding and agreement between the parties with regard to the subjects
hereof and thereof.

            2.5 Notices, etc. All notices and other communications required or
permitted hereunder shall be in writing and shall be mailed by first class mail,
postage prepaid, certified or registered mail, return receipt requested, or by
personal delivery (subject to evidence of receipt) or by overnight courier
(subject to evidence of receipt) addressed (a) if to Holder, at such Holder's
address(es) as set forth below, or at such other address(es) as such Holder
shall have furnished to the Company in writing, or (b) if to the Company, at the
Company's address set forth below, or at such other address as the Company shall
have furnished to the Holder in writing.

            2.6 Severability. In case any provision of this Agreement shall be
invalid, illegal, or unenforceable, the validity, legality and enforceability of
the remaining provisions of this Agreement or any provision of the other
Agreement s shall not in any way be affected or impaired thereby.

            2.7 Titles and Subtitles. The titles of the sections and subsections
of this Agreement are for convenience of reference only and are not to be
considered in construing this Agreement.

            2.8 Counterparts. This Agreement may be executed in any number of
counterparts, each of which shall be an original, but all of which together
shall constitute one instrument.


<PAGE>



         IN WITNESS WHEREOF, the parties have caused this Registration Rights
Agreement to be executed by their duly authorized representatives as of the date
first above written.

PURCHASER                                   COMPANY
SILICON VALLEY BANK                         GREENFIELD ONLINE, INC.


By:______________________________           By:_________________________________
Name:____________________________           Name:_______________________________
Title:___________________________           Title:______________________________
Address:_________________________           Address: 15 River Road
                                                     Wilton, Connecticut 06897

copy to:  Silicon Valley Bank
          Treasury Department
          3003 Tasman Drive, HA-200
          Santa Clara, CA 95054