<PAGE>

                                                                    EXHIBIT 10.5

                               PLEDGE AGREEMENT

     This PLEDGE AGREEMENT (this "Agreement") is dated as of August 18th, 2000,
and entered into by and between NEVE RICHARD SAVAGE and ANN ELIZABETH SAVAGE
(collectively, "Pledgor") and AVENUE A, INC. ("Secured Party").

                            PRELIMINARY STATEMENTS

     A.   Pledgor is the legal and beneficial owner of the shares of stock (the
"Pledged Shares") described in Schedule I annexed hereto and issued by Secured
Party.

     B.   Secured Party has entered into a Loan Agreement dated as of August
18th, 2000 (the "Loan Agreement", the terms defined therein and not otherwise
defined herein being used herein as therein defined) with Pledgor, pursuant to
which Lender has a commitment, subject to the terms and conditions set forth in
the Loan Agreement, to extend certain credit to Pledgor.

     C.   It is a condition precedent to the initial extensions of credit by
Lender under the Loan Agreement that Pledgor shall have granted the security
interests and undertaken the obligations contemplated by this Agreement.

     NOW, THEREFORE, in consideration of the premises and in order to induce
Lender to make the Loan under the Loan Agreement and for other good and valuable
consideration, the receipt and adequacy of which are hereby acknowledged,
Pledgor hereby agrees with Secured Party as follows:

1.   Pledge of Security

     Pledgor hereby pledges and assigns to Secured Party, and hereby grants to
Secured Party a security interest in, all of Pledgor's right, title and interest
in and to the following (the "Pledged Collateral"):

     (a)  The Pledged Shares and the certificates representing the Pledged
Shares and any interest of Pledgor in the entries on the books of any financial
intermediary pertaining to the Pledged Shares, and all dividends, cash,
warrants, rights, instruments and other property or proceeds from time to time
received, receivable or otherwise distributed in respect of or in exchange for
any or all of the Pledged Shares;

                                                                          PAGE 1
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     (b)  To the extent not covered by clause (a) above, all proceeds of any or
all of the foregoing Pledged Collateral. For purposes of this Agreement, the
term "proceeds" includes whatever is receivable or received when Pledged
Collateral or proceeds are sold, exchanged, collected or otherwise disposed of,
whether such disposition is voluntary or involuntary, and includes, without
limitation, proceeds of any indemnity or guaranty payable to Pledgor or Secured
Party from time to time with respect to any of the Pledged Collateral.

2.   Security for Obligations

     This Agreement secures, and the Pledged Collateral is collateral security
for, the prompt payment or performance in full when due, whether at stated
maturity, by required prepayment, declaration, acceleration, demand or otherwise
(including the payment of amounts that would become due but for the operation of
the automatic stay under Section 362(a) of the Bankruptcy Code, 11 U.S.C. (S)
362(a)), of all obligations and liabilities of every nature of Pledgor now or
hereafter existing under or arising out of or in connection with the Loan
Agreement and the other Loan Documents and all extensions or renewals thereof,
whether for principal, interest (including without limitation interest that, but
for the filing of a petition in bankruptcy with respect to Pledgor would accrue
on such obligations), fees, expenses, indemnities or otherwise, whether
voluntary or involuntary, direct or indirect, absolute or contingent, liquidated
or unliquidated, whether or not jointly owed with others, and whether or not
from time to time decreased or extinguished and later increased, created or
incurred, and all or any portion of such obligations or liabilities that are
paid, to the extent all or any part of such payment is avoided or recovered
directly or indirectly from Secured Party or any Lender as a preference,
fraudulent transfer or otherwise (all such obligations and liabilities being the
"Underlying Debt"), and all obligations of every nature of Pledgor now or
hereafter existing under this Agreement (all such obligations of Pledgor,
together with the Underlying Debt, being the "Secured Obligations").

3.   Delivery of Pledged Collateral

     All certificates or instruments representing or evidencing the Pledged
Collateral shall be delivered to and held by or on behalf of Secured Party
pursuant hereto and shall be in suitable form for transfer by delivery or, as
applicable, shall be accompanied by Pledgor's endorsement, where necessary, or
duly executed instruments of transfer or assignment in blank, all in form and
substance satisfactory to Secured Party. Secured Party shall have the right at
any time to exchange certificates or instruments representing or evidencing
Pledged Collateral for certificates or instruments of smaller or larger
denominations.

                                                                          PAGE 2
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4.   Transfers and Other Liens, Additional Pledged Collateral; Etc.

     Pledgor shall:

     (a)  Not, except as expressly permitted by the Loan Agreement, (i) sell,
assign (by operation of law or otherwise) or otherwise dispose of, or grant any
option with respect to, any of the Pledged Collateral, or (ii) create or suffer
to exist any Lien upon or with respect to any of the Pledged Collateral, except
for the security interest under this Agreement; and

     (b)  Promptly deliver to Secured Party all written notices received by it
with respect to the Pledged Collateral.

5.   Further Assurances; Pledge Amendments

     (a)  Pledgor agrees that from time to time, at the expense of Pledgor,
Pledgor will promptly execute and deliver all further instruments and documents,
and take all further action, that reasonably may be necessary or desirable, or
that Secured Party reasonably may request, in order to perfect and protect any
security interest granted or purported to be granted hereby or to enable Secured
Party to exercise and enforce its rights and remedies hereunder with respect to
any Pledged Collateral. Without limiting the generality of the foregoing,
Pledgor will: (i) execute and file such financing or continuation statements, or
amendments thereto, and such other instruments or notices, as reasonably may be
necessary or desirable, or as Secured Party reasonably may request, in order to
perfect and preserve the security interests granted or purported to be granted
hereby and (ii) at Secured Party's reasonable request, appear in and defend any
action or proceeding that may affect Pledgor's title to or Secured Party's
security interest in all or any part of the Pledged Collateral.

     (b)  Pledgor further agrees that, upon obtaining any additional shares of
stock of a result of a split, dividend, combination, or similar transaction,
such shares shall be deemed to be Pledged Shares, and Pledgor will promptly (and
in any event within five Business Days) deliver to Secured Party a Pledge
Amendment, duly executed by Pledgor, in substantially the form of Schedule II
annexed hereto (a "Pledge Amendment"), in respect of the additional Pledged
Shares to be pledged pursuant to this Agreement. Pledgor hereby authorizes
Secured Party to attach each Pledge Amendment to this Agreement and agrees that
all Pledged Shares listed on any Pledge Amendment delivered to Secured Party
shall for all purposes hereunder be considered Pledged Collateral; provided that
                                                                   --------
the failure of Pledgor to execute a Pledge Amendment with respect to any
additional Pledged Shares pledged pursuant to this Agreement shall not impair
the security interest of Secured Party therein or otherwise

                                                                          PAGE 3
<PAGE>

adversely affect the rights and remedies of Secured Party hereunder with respect
thereto.

6.   Voting Rights; Dividends, Etc.

     So long as no Event of Default shall have occurred and be continuing,
Pledgor shall be entitled to exercise any and all voting and other consensual
rights pertaining to the Pledged Shares or any part thereof for any purpose not
inconsistent with the terms of this Agreement or the Loan Agreement.

7.   Secured Party Appointed Attorney-in-Fact

     Pledgor hereby irrevocably appoints Secured Party as Pledgor's attorney-in-
fact, with full authority in the place and stead of Pledgor and in the name of
Pledgor, Secured Party or otherwise, from time to time in Secured Party's
discretion to take any action and to execute any instrument that Secured Party
reasonably may deem necessary or advisable to accomplish the purposes of this
Agreement, including without limitation:

     (a)  To file one or more financing or continuation statements, or
amendments thereto, relative to all or any part of the Pledged Collateral
without the signature of Pledgor;

     (b)  To receive, endorse and collect any instruments made payable to
Pledgor representing any dividend, principal or interest payment or other
distribution in respect of the Pledged Collateral or any part thereof and to
give full discharge for the same; and

     (c)  To instruct a broker to sell the Pledged Collateral pursuant to the
terms of this Agreement and the Secured Obligations.

8.   Secured Party May Perform

     If Pledgor fails to perform any agreement contained herein, Secured Party
may itself perform, or cause performance of, such agreement, and the reasonable
expenses of Secured Party incurred in connection therewith shall be payable by
Pledgor under Section 13(b).

9.   Standard of Care

     The powers conferred on Secured Party hereunder are solely to protect its
interest in the Pledged Collateral and shall not impose any duty upon it to
exercise any such powers. Except for the exercise of reasonable care in the
custody of any Pledged

                                                                          PAGE 4
<PAGE>

Collateral in its possession and the accounting for moneys actually received by
it hereunder, Secured Party shall have no duty as to any Pledged Collateral, it
being understood that Secured Party shall have no responsibility for (a)
ascertaining or taking action with respect to calls, conversions, exchanges,
maturities, tenders or other matters relating to any Pledged Collateral, whether
or not Secured Party has or is deemed to have knowledge of such matters, (b)
taking any necessary steps (other than steps taken in accordance with the
standard of care set forth above to maintain possession of the Pledged
Collateral) to preserve rights against any parties with respect to any Pledged
Collateral, (c) taking any necessary steps to collect or realize upon the
Secured Obligations or any guarantee therefor, or any part thereof, or any of
the Pledged Collateral, or (d) initiating any action to protect the Pledged
Collateral against the possibility of a decline in market value. Secured Party
shall be deemed to have exercised reasonable care in the custody and
preservation of Pledged Collateral in its possession if such Pledged Collateral
is accorded treatment substantially equal to that which Secured Party accords
its own property consisting of negotiable securities.

10.  Remedies

     (a)  If any Event of Default shall have occurred and be continuing, Secured
Party may exercise in respect of the Pledged Collateral, in addition to all
other rights and remedies provided for herein or otherwise available to it, all
the rights and remedies of a secured party on default under the Uniform
Commercial Code as in effect in any relevant jurisdiction (the "Code") (whether
or not the Code applies to the affected Pledged Collateral).

     (b)  Pledgor recognizes that, by reason of certain prohibitions contained
in the Securities Act and applicable state securities laws, Secured Party may be
compelled, with respect to any sale of all or any part of the Pledged Collateral
conducted without prior registration or qualification of such Pledged Collateral
under the Securities Act and/or such state securities laws, to limit purchasers
to those who will agree, among other things, to acquire the Pledged Collateral
for their own account, for investment and not with a view to the distribution or
resale thereof. Pledgor acknowledges that any such private sales may be at
prices and on terms less favorable than those obtainable through a public sale
without such restrictions (including, without limitation, a public offering made
pursuant to a registration statement under the Securities Act) and,
notwithstanding such circumstances, Pledgor agrees that the conduct of a private
sale shall be commercially reasonable under the circumstances and that Secured
Party shall have no obligation to engage in public sales and no obligation to
delay the sale of any Pledged Collateral for the period of time necessary to
permit the issuer thereof to register it for a form of public sale requiring
registration under the Securities Act or under applicable state securities laws,
even if such issuer would, or should, agree to so register it.

                                                                          PAGE 5
<PAGE>

11.  Planned Sales

     During the week concluding on the 2/nd/ Friday of the third month in each
calendar quarter, commencing with the week ending September 8, 2000, 15,000
shares of the Pledged Shares shall be sold and applied according to the
priorities set forth in Paragraph 12 of this Agreement; provided, however, any
sales by Pledgor shall remain subject to the pre-clearance and other
requirements of Avenue A's insider trading policy.

12.  Application of Proceeds

     Except as expressly provided elsewhere in this Agreement, all proceeds
received by Secured Party in respect of any sale of, collection from, or other
realization upon all or any part of the Pledged Collateral may, in the
discretion of Secured Party, be held by Secured Party as Pledged Collateral for,
and/or then, or at any time thereafter, applied in full or in part by Secured
Party against, the Secured Obligations in the following order of priority:

     (a)  FIRST: To the payment of all costs and expenses of such sale,
collection or other realization, including reasonable compensation to Secured
Party and its agents and counsel, and all other expenses, liabilities and
advances made or incurred by Secured Party in connection therewith, and all
amounts for which Secured Party is entitled to indemnification hereunder and all
advances made by Secured Party hereunder for the account of Pledgor, and to the
payment of all costs and expenses paid or incurred by Secured Party in
connection with the exercise of any right or remedy hereunder, all in accordance
with Section 13;

     (b)  SECOND: To the payment to Pledgor in the amount of the taxes owed by
Pledgor on account of such sale;

     (c)  THIRD: To the payment of any currently due or past due indebtedness to
igroup2 limited pursuant to a debt secured by a first legal charge on Pledgor's
London residence.

     (d)  FOURTH: To the payment of all Secured Obligations in such order as
Secured Party shall elect; and

     (e)  FIFTH: To the payment to or upon the order of Pledgor, or to whosoever
may be lawfully entitled to receive the same or as a court of competent
jurisdiction may direct, of any surplus then remaining from such proceeds.

                                                                          PAGE 6
<PAGE>

13.  Indemnity and Expenses

     (a)  Pledgor agrees to indemnify Secured Party and each Lender from and
against any and all claims, losses and liabilities in any way relating to,
growing out of or resulting from this Agreement and the transactions
contemplated hereby (including, without limitation, enforcement of this
Agreement), except to the extent such claims, losses or liabilities result
solely from Secured Party's or such Lender's gross negligence or willful
misconduct as finally determined by a court of competent jurisdiction.

     (b)  Pledgor will pay to Secured Party upon demand the amount of any and
all costs and expenses, including the reasonable fees and expenses of its
counsel and of any experts and agents, that Secured Party may incur in
connection with (i) the administration of this Agreement, (ii) the custody or
preservation of, or the sale of, collection from, or other realization upon, any
of the Pledged Collateral, (iii) the exercise or enforcement of any of the
rights of Secured Party hereunder, or (iv) the failure by Pledgor to perform or
observe any of the provisions hereof.

14.  Continuing Security Interest

     (a)  This Agreement shall create a continuing security interest in the
Pledged Collateral and shall (a) remain in full force and effect until the
indefeasible payment in full of all Secured Obligations and the cancellation or
termination of the Commitments, (b) be binding upon Pledgor, its successors and
assigns, and (c) inure, together with the rights and remedies of Secured Party
hereunder, to the benefit of Secured Party and its successors, transferees and
assigns. Subject to subsection 13(b) below, upon the payment in full of all
Secured Obligations, the security interest granted hereby shall terminate and
all rights to the Pledged Collateral shall revert to Pledgor. Upon any such
termination Secured Party will, at Pledgor's expense, execute and deliver to
Pledgor such documents as Pledgor shall reasonably request to evidence such
termination and Pledgor shall be entitled to the return, upon its request and at
its expense, against receipt and without recourse to Secured Party, of such of
the Pledged Collateral as shall not have been sold or otherwise applied pursuant
to the terms hereof.

     (b)  In the event that all or any portion of the Secured Obligations are
paid, the obligations of Pledgor hereunder shall continue and remain in full
force and effect or be reinstated, as the case may be, in the event that all or
any part of such payment(s) are rescinded or recovered directly or indirectly
from Agent or any Lender as a preference, fraudulent transfer or otherwise, and
any such payments which are so rescinded or recovered shall constitute Secured
Obligations for all purposes of this Agreement.

                                                                          PAGE 7
<PAGE>

15.  Amendments, Etc.

     No amendment or waiver of any provision of this Agreement, or consent to
any departure herefrom, shall in any event be effective unless the same shall be
in writing and signed by the party against whom it is sought to be enforced ,
and then such waiver or consent shall be effective only in the specific instance
and for the specific purpose for which it was given.

16.  Notices

     Any notice or other communication herein required or permitted to be given
shall be in writing and may be personally served, telecopied, telexed or sent by
United States mail or courier service and shall be deemed to have been given
when delivered in person or by courier service, upon receipt of telecopy or
telex, or four Business Days after depositing it in the United States mail,
registered or certified, with postage prepaid and properly addressed. For the
purposes hereof, the address of each party hereto shall be as set forth under
such party's name on the signature pages hereof or, as to either party, such
other address as shall be designated by such party in a written notice delivered
to the other party hereto.

17.  Failure or Indulgence Not Waiver; Remedies Cumulative

     No failure or delay on the part of Secured Party in the exercise of any
power, right or privilege hereunder shall impair such power, right or privilege
or be construed to be a waiver of any default or acquiescence therein, nor shall
any single or partial exercise of any such power, right or privilege preclude
any other or further exercise thereof or of any other power, right or privilege.
All rights and remedies existing under this Agreement are cumulative to, and not
exclusive of, any rights or remedies otherwise available.

18.  Severability

     In case any provision in or obligation under this Agreement shall be
invalid, illegal or unenforceable in any jurisdiction, the validity, legality
and enforceability of the remaining provisions or obligations, or of such
provision or obligation in any other jurisdiction, shall not in any way be
affected or impaired thereby.

19.  Headings

     Section and subsection headings in this Agreement are included herein for
convenience of reference only and shall not constitute a part of this Agreement
for any other purpose or be given any substantive effect.

                                                                          PAGE 8
<PAGE>

20.  Governing Law; Terms

     THIS AGREEMENT SHALL BE GOVERNED BY, AND SHALL BE CONSTRUED AND ENFORCED IN
ACCORDANCE WITH, THE INTERNAL LAWS OF THE STATE OF WASHINGTON, WITHOUT REGARD TO
CONFLICTS OF LAWS PRINCIPLES, EXCEPT TO THE EXTENT THAT THE CODE PROVIDES THAT
THE VALIDITY OR PERFECTION OF THE SECURITY INTEREST HEREUNDER, OR REMEDIES
HEREUNDER, IN RESPECT OF ANY PARTICULAR PLEDGED COLLATERAL ARE GOVERNED BY THE
LAWS OF A JURISDICTION OTHER THAN THE STATE OF WASHINGTON. Unless otherwise
defined herein or in the Loan Agreement, terms used in Article 9 of the Uniform
Commercial Code in the State of Washington are used herein as therein defined.

20.  Consent to Jurisdiction and Service of Process

     ALL JUDICIAL PROCEEDINGS BROUGHT AGAINST PLEDGOR ARISING OUT OF OR RELATING
TO THIS AGREEMENT MAY BE BROUGHT IN ANY STATE OR FEDERAL COURT OF COMPETENT
JURISDICTION IN THE STATE OF WASHINGTON, AND BY EXECUTION AND DELIVERY OF THIS
AGREEMENT PLEDGOR ACCEPTS FOR ITSELF AND IN CONNECTION WITH ITS PROPERTIES,
GENERALLY AND UNCONDITIONALLY, THE NONEXCLUSIVE JURISDICTION OF THE AFORESAID
COURTS AND WAIVES ANY DEFENSE OF FORUM NON CONVENIENS AND IRREVOCABLY AGREES TO
BE BOUND BY ANY JUDGMENT RENDERED THEREBY IN CONNECTION WITH THIS AGREEMENT.
Pledgor hereby agrees that service of process sufficient for personal
jurisdiction in any action against Pledgor in the State of Washington may be
made by registered or certified mail, return receipt requested, to Pledgor at
its address as provided in Section 18 and Pledgor hereby acknowledges that such
service shall be effective and binding in every respect. Nothing herein shall
affect the right to serve process in any other manner permitted by law or shall
limit the right of Pledgor or Secured Party to bring proceedings in the courts
of any other jurisdiction, or to object thereto.

21.  Waiver of Jury Trial

     PLEDGOR AND SECURED PARTY HEREBY AGREE TO WAIVE THEIR RESPECTIVE RIGHTS TO
A JURY TRIAL OF ANY CLAIM OR CAUSE OF ACTION BASED UPON OR ARISING OUT OF THIS
AGREEMENT. The scope of this waiver is intended to be all-encompassing of any
and all disputes that may be filed in any court and that relate to the subject
matter of this transaction, including without limitation contract claims, tort
claims, breach of duty claims, and all other

                                                                          PAGE 9
<PAGE>

common law and statutory claims. Pledgor and Secured Party each acknowledge that
this waiver is a material inducement for Pledgor and Secured Party to enter into
a business relationship, that Pledgor and Secured Party have already relied on
this waiver in entering into this Agreement and that each will continue to rely
on this waiver in their related future dealings. Pledgor and Secured Party
further warrant and represent that each has reviewed this waiver with its legal
counsel, and that each knowingly and voluntarily waives its jury trial rights
following consultation with legal counsel. THIS WAIVER IS IRREVOCABLE, MEANING
THAT IT MAY NOT BE MODIFIED EITHER ORALLY OR IN WRITING, AND THIS WAIVER SHALL
APPLY TO ANY SUBSEQUENT AMENDMENTS, RENEWALS, SUPPLEMENTS OR MODIFICATIONS TO
THIS AGREEMENT. In the event of litigation, this Agreement may be filed as a
written consent to a trial by the court.

22.  Counterparts

     This Agreement may be executed in one or more counterparts and by different
parties hereto in separate counterparts, each of which when so executed and
delivered shall be deemed an original, but all such counterparts together shall
constitute but one and the same instrument; signature pages may be detached from
multiple separate counterparts and attached to a single counterpart so that all
signature pages are physically attached to the same document.

            [The remainder of this page intentionally left blank.]

                                                                         PAGE 10
<PAGE>

     ORAL AGREEMENTS OR ORAL COMMITMENTS TO LOAN MONEY, EXTEND CREDIT, OR
FORBEAR FROM ENFORCING REPAYMENT OF A DEBT ARE NOT ENFORCEABLE UNDER WASHINGTON
LAW.

     IN WITNESS WHEREOF, Pledgor and Secured Party have caused this Agreement to
be duly executed and delivered by their respective officers thereunto duly
authorized as of the date first written above.

                               /s/ NEVE SAVAGE
                               ----------------------------------------------
                               NEVE RICHARD SAVAGE

                               /s/ A. SAVAGE
                               ----------------------------------------------
                               ANN ELIZABETH SAVAGE

                               AVENUE A, INC.

                               By: /s/ J. J. MILLER
                               ----------------------------------------------
                               Title: Jeffrey J. Miller
                                      ---------------------------------------
                                      Vice President
                                      ---------------------------------------
                                      Corporate Development and Legal Affairs
                                      ---------------------------------------
                                      Avenue A, Inc.
                                      ---------------------------------------

                                                                         PAGE 11
<PAGE>

                                  SCHEDULE I
                              to Pledge Agreement

================================================================================
    Certificate    Stock Issuer       Class          Nos.     Par     Shares
================================================================================
1                    Avenue A         Common       AVE 0658   $.01    39,750
--------------------------------------------------------------------------------
2                    Avenue A         Common       AVE 0660   $.01    80,250
================================================================================

                                                                         PAGE 12
<PAGE>

                                  SCHEDULE II
                              to Pledge Agreement

                               PLEDGE AMENDMENT

     This Pledge Amendment, dated __________, is delivered pursuant to Section
5(b) of the Pledge Agreement referred to below. The undersigned hereby agrees
that this Pledge Amendment may be attached to the Pledge Agreement dated August
___, 2000, (the "Pledge Agreement"), between the undersigned and Avenue A, Inc.,
as Secured Party (capitalized terms defined therein being used herein as therein
defined), and that the Pledged Shares listed on this Pledge Amendment shall be
deemed to be part of the Pledged Shares and shall become part of the Pledged
Collateral and shall secure all Secured Obligations.

                                             _________________________________
                                             NEVE RICHARD SAVAGE

                                             _________________________________
                                             ANN ELIZABETH SAVAGE

================================================================================
                                    Debt       Amount
     Cert. Nos.   Stock Issuer     Issuer      of Debt      Value     Shares
================================================================================

--------------------------------------------------------------------------------

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

                                                                         PAGE 13