<PAGE>

                                                                   Exhibit 10.10

                             Ziff Davis Media Inc.
                              28 East 28th Street
                           New York, New York 10016


                                 January 19, 2001

ZDNet, Inc.
CNET Networks, Inc.
28 East 28th Street
New York, NY 10016
Attention: Daniel Rosensweig

                Re:  Amendment to License Agreement
                     ------------------------------

Dear Dan:

     This letter agreement (this "Agreement") amends certain terms of the
License Agreement (the "License Agreement") dated as of April 5, 2000 by and
between ZDNet, Inc., formerly Ziff-Davis Inc., a Delaware corporation ("ZDNet"),
and Ziff Davis Media Inc., a Delaware corporation ("Ziff Davis Media"), and sets
forth certain other agreements between the parties hereto.  Capitalized terms
used in this Agreement and not otherwise defined will have the meanings ascribed
to such terms in the License Agreement.  ZDNet, CNET Networks, Inc. ("CNET"),
and Ziff Davis Media agree as follows:

A.  LICENSE AGREEMENT


    1.  The License Agreement, including the licenses granted by Ziff Davis
        Media to ZDNet thereunder with respect to both U.S. and foreign
        Publications, will terminate and be of no further force or effect on
        midnight February 28, 2002 (the "License Agreement Termination Date").
        From and after the License Agreement Termination Date, neither ZDNet,
        CNET, nor any of their affiliates, successors, assigns or licensees will
        have any right to (i) translate, reproduce, publicly display, transmit
        or distribute Content (including, without limitation, archival Content
        of the Publications), except as permitted by fair use or other similar
        laws, or (ii) use the Trademarks. Notwithstanding the foregoing,
        Sections 10, 11, 14, 16(i), the second sentence of 16(ii), 16(iii) and
        18 of the License Agreement will survive the expiration or termination
        of the License Agreement.

    2.  Ziff Davis Media's obligation in Section 1(i) of the License Agreement
        to cause the purchaser of any Publication to agree to assume and carry
        out the obligations

                                      -1-
<PAGE>

        of Ziff Davis Media under the License Agreement with respect to that
        Publication shall continue until the License Agreement Termination Date
        and any purchaser shall also assume all of Ziff Davis Media's
        obligations under this Agreement that pertain to such Publication.

3.      (a) The licenses granted to ZDNet under the License Agreement to
        translate, reproduce, publicly display, transmit or distribute Content
        online and through electronic distribution via the World Wide Web, the
        Internet or any technology hereafter developed and used for similar
        purposes or evolutions or migrations thereof, to grant third parties the
        right to distribute Content as described above (including Content from
        the non-U.S. Publications) and to use the Trademarks in connection
        therewith, shall remain exclusive through and including February 28,
        2001.

        (b) Effective March 1, 2001 and continuing through the License Agreement
            Termination Date, any and all exclusive licenses under the License
            Agreement shall become non-exclusive, and ZDNet and CNET, on the one
            hand, and Ziff Davis Media and its affiliates, on the other hand,
            shall have the non-exclusive right to, and (subject to the
            limitations set forth elsewhere in this Paragraph 3 and the other
            requirements set forth in the License Agreement as amended by this
            Agreement) the right to grant licenses to third parties to,
            translate, reproduce, publicly display, transmit or distribute
            Content through any means or media, including, without limitation,
            electronic distribution via the World Wide Web, the Internet or any
            technology hereafter developed and used for similar purposes or
            evolutions or migrations thereof. Effective March 1, 2001 and
            continuing through the License Agreement Termination Date, the
            Content may be used by both ZDNet and CNET as permitted by the terms
            of the License Agreement as amended by this Agreement. If for any
            reason, Ziff Davis Media does not provide any Publication Content to
            ZDNet in accordance with the manner and timing of distribution prior
            to the date hereof or in accordance with the requirements of
            Paragraph 3(e), then, neither Ziff Davis Media nor any if its
            affiliates shall use itself, or permit any third party to use, in
            any manner online, the Content which has not been so delivered until
            such time as it has been delivered to ZDNet. The preceding sentence
            shall be ZDNet's sole remedy with respect to any failure by Ziff
            Davis Media to deliver Content from the PC Expert Publication in
            France, however, it shall be ZDNet's non-exclusive remedy, in
            addition to any breach of contract or other claim, with regard to
            any failure to provide Content from any Publication other than PC
            Expert.

        (c)  Notwithstanding the foregoing or anything to the contrary contained
             in the License Agreement, but subject to Ziff Davis Media's rights
             under Section 1(ii) of the License Agreement, Ziff Davis Media
             shall not license Content

                                      -2-
<PAGE>

             from any of the Publications to any of the third parties identified
             as Tier 1 listed on the attached Schedule 1 until March 1, 2002, or
                                              ----------
             to any of the third parties identified as Tier 2 listed on the
             attached Schedule 1 until December 1, 2001, in each case, as such
                      ----------
             Schedule may be modified from time to time by written notice from
             ZDNet to reflect new sublicenses of Content as permitted below. The
             content sublicenses with the parties listed on Schedule 1 are
             referred to as the "Restricted Arrangements". During the period
             from March 1, 2001 through March 1, 2002, ZDNet will have the
             continuing right under, and subject to the terms and conditions of,
             Section 2 of the License Agreement to enter into new Content
             sublicense arrangements, to add those arrangements to Schedule 1
             and such new arrangements shall be considered Restricted
             Arrangements (but only to the extent such sublicenses were entered
             into after the date of this Agreement and only with respect to
             entities which Ziff Davis Media has not notified ZDNet that it has
             a Content license agreement with), provided that in all events
             ZDNet's right to license the Content (and the licenses so granted
             as they apply to the Content) shall terminate on the License
             Agreement Termination Date. Until the License Agreement Termination
             Date, each party shall provide the other party with written
             notification of all new third party Content license agreements
             within five (5) days of entering into such arrangements.
             Notwithstanding the foregoing, until March 1, 2002, neither ZDNet
             or CNET, on the one hand, nor Ziff Davis Media or its affiliates on
             the other hand, will license any Publication Content to any of the
             following entities or their affiliates (as such term is defined in
             Section 13): International Data Group, Inc., CMP Media, Inc.,
             United News & Media PLC, or Imagine Media, Inc. The preceding list
             of entities shall replace in its entirety the list of Ziff Davis
             Media competitors in Schedule 7.1(i) referred to in Section 2(i)(A)
             of the License Agreement.

        (d)  Notwithstanding anything in this Agreement to the contrary, ZDNet
             will remain obligated to make the royalty payments to Ziff Davis
             Media contemplated by the last paragraph of Section 2(i) of the
             License Agreement in respect of the Restricted Arrangements.

        (e)  From March 1, 2001 through the License Agreement Termination Date,
             Ziff Davis Media shall provide ZDNet with Content from the
             Publications as soon as the particular issue (or portion thereof)
             is completed for transmission to the printer, or on such earlier
             date as any item of Content is released in any media. In the event
             that issues or specific stories are marked with an embargo date
             that applies universally to Ziff Davis Media and all of its
             licensees, ZDNet agrees to honor such embargo dates and to ensure
             that the information remains confidential until those dates.

                                      -3-
<PAGE>

4.  (a) ZDNet's right and obligation to host the Websites of each U.S.
    Publication as provided in Section 3 of the License Agreement and ZDNet's
    license to use the Trademarks (including, without limitation, the urls)
    which relate to each U.S. Publication, will terminate with respect to each
    particular U.S. Publication in accordance with the following schedule:


<TABLE>
<CAPTION>

                   Publication                                 Website Hosting
                   -----------                                 Termination Date
                                                               ----------------
<S>                                                            <C>
 Family PC                                                      April 1, 2001

 Yahoo! Internet Life,Computer Gaming World, Expert             May 1, 2001
 Gamer, Electronic Gaming Monthly, Official U.S.
 Playstation Magazine

 PC Magazine                                                    July 1, 2001

 Interactive Week                                               September 1, 2001

 Ziff Davis Smart Business for the New Economy; eWeek           October 1

 Smart Partner                                                  November 1, 2001
</TABLE>

    ZDNet's right and obligation to host the Websites of each non-U.S.
    Publication as provided in Section 3 of the License Agreement and ZDNet's
    license to use the Trademarks (including, without limitation, the urls)
    which relate to each non-U.S. Publication, will terminate with respect to
    each particular non-U.S. Publication on the License Agreement Termination
    Date (which License Agreement Termination Date shall be deemed the Website
    Hosting Termination Date (as defined below) for the non-U.S. Publications
    for purposes of this Agreement). On the applicable date on which ZDNet's
    Website hosting rights and obligations and Trademark licensing rights
    terminate with respect to a particular Publication (each, a "Website Hosting
    Termination Date"), as between ZDNet/CNET and Ziff Davis Media, only Ziff
    Davis Media and its affiliates will have the right to host, maintain and
    produce the Website with respect to the applicable Publication and to use
    exclusively the applicable Trademarks.

    (b) ZDNet will continue to post the ZDNet home page links described in
    Section 3(v)(A) of the License Agreement for a particular Publication until
    the Website Hosting Termination Date for such Publication. Beginning on the
    first

                                      -4-
<PAGE>

    Website Hosting Termination Date, ZDNet and CNET, on the one hand, and Ziff
    Davis Media and its affiliates, on the other hand, will display statements
    that such party's Websites are not affiliated with the Websites of the other
    party, as well as links directing users to the other party's Websites. The
    links shall be posted for a period of 120 days from each applicable Website
    Hosting Termination Date in a form to be mutually agreed upon by the
    parties. The links will be located on each page of any Website of Ziff Davis
    Media or its affiliates which includes Publication Content and each page of
    any Website of ZDNet or CNET which includes Publication Content. The links
    on the Ziff Davis Media and affiliates' Websites will be of the same size
    and placement on the page as those on the ZDNet and CNET Websites, such
    size, design and placement shall be mutually agreed upon by the parties.

    (c)  On the Website Hosting Termination Date for Yahoo! Internet Life, ZDNet
    will deliver to Ziff Davis Media an archive in XML format of the Daily Net
    Buzz, Joke of the Day, and the other daily Yahoo! Internet Life content
    linked to from the home page of that Publication Website (the "YILO Daily
    Content") which will include the YILO Daily Content for the one year period
    prior to such Website Hosting Termination Date. On the Website Hosting
    Termination Date for PC Magazine, ZDNet will deliver to Ziff Davis Media an
    archive in XML format of the PC Magazine First Looks (the "First Looks")
    which will include the First Looks for the one year period prior to such
    Website Hosting Termination Date.


5.  (a)  For the period prior to the applicable Website Hosting Termination
    Date, Section 3(ii) is hereby modified such that ZDNet will not be obligated
    to make any enhancements or material modifications to the Publication
    Websites (other than bug fixes and technical upgrades) beyond such Websites
    current form, unless approved by ZDNet (which approval will not be
    unreasonably withheld or delayed) and paid for by Ziff Davis Media. For
    purposes of clarity, the preceding sentence shall not limit ZDNet's right to
    cease enhancements as permitted under Paragraph 6 below. Notwithstanding the
    foregoing, but assuming Ziff Davis Media's compliance with its obligations
    below to make any former ZDNet employees it hires available for services,
    ZDNet agrees to post material on the Publication Websites in a timely
    fashion until each applicable Website Hosting Termination Date.

    (b)  Effective on each applicable Website Hosting Termination Date, ZDNet's
    obligations under Section 3(iv) of the License Agreement that pertain to
    Publication email newsletter distribution for the applicable Publication
    Website shall terminate and ZDNet shall have no further obligations
    thereunder with respect to such Publication Website. Effective on March 1,
    2001, ZDNet shall no longer have any obligation to acquire additional

                                      -5-
<PAGE>

    subscribers for such newsletters, but shall continue to include newsletter
    subscriptions as part of its registration process until the applicable
    Website Hosting Termination Date.

    (c)  If, prior to a Website Hosting Termination Date, Ziff Davis Media hires
    (or has hired) a ZDNet employee who had worked for ZDNet in connection with
    the hosting or production of a Publication Website, Ziff Davis Media will
    make such employee reasonably available to ZDNet to assist in performing his
    or her prior responsibilities for such Publication Website, until the
    Website Hosting Termination Date for such Publication. ZDNet shall have no
    further obligation to provide, or to provide Ziff Davis Media funding for,
    any editorial positions for the Publication Websites pursuant to Section
    3(vi) of the License Agreement. The preceding sentences shall not affect
    ZDNet's obligation to continue hosting and posting Content for each
    Publication Website, or to continue to fund such hosting and posting, until
    the applicable Website Hosting Termination Date.

6.  For the period prior to the applicable Website Hosting Termination Date, the
    second sentence of Section 3(iii) is hereby modified such that ZDNet will
    continue to have the right (but not the obligation) to include content it
    creates or licenses in a Publication Website, but only to the extent ZDNet
    currently includes such additional content. All other provisions of Section
    3(iii) shall terminate with respect to a particular Publication Website on
    the applicable Website Hosting Termination Date. ZDNet's obligations in
    Section 3(viii) of the License Agreement regarding the payment to Yahoo! of
    twenty percent of Advertising Revenue and regarding ZDNet's obligation to
    host that Publication Website shall terminate on the Website Hosting
    Termination Date for the Yahoo! Internet Life Publication. The parties'
    obligations under Section 4 of the License Agreement shall terminate
    effective as of March 1, 2001.

7.  ZDNet will continue to make royalty payments to Ziff Davis Media pursuant to
    Section 5 of the License Agreement for all periods through March 1, 2001.
    The final royalty payment (in respect of January and February 2001) will be
    made not later than March 25, 2001. For purposes of clarity, the royalty
    payments will be calculated as described in such section taking into account
    solely the gross revenues of ZDNet and its subsidiaries (subject to the
    exclusions listed in such section ) and will not include the revenues of the
    other businesses of CNET. From and after the License Agreement Termination
    Date, ZDNet will not be obligated to make any royalty payments under Section
    5 of the License Agreement. In consideration of the elimination, after March
    1, 2001, of all royalty obligations under Section 5 of the License
    Agreement, ZDNet shall pay Ziff Davis Media a License Agreement termination
    fee in the total amount of $4.5

                                      -6-
<PAGE>

    million, payable in cash as follows: $2.2 million due on March 1, 2001, and
    $2.3 million due on March 1, 2002.

8.  ZDNet's rights under the first sentence of Section 6(i) of the License
    Agreement will terminate on March 1, 2002 and may be exercised by either
    ZDNet or its affiliates, including, CNET. Ziff Davis Media's obligations
    under Section 6(i) of the License Agreement to include the urls of the
    Publication Websites hosted by ZDNet on the cover and the table of contents
    of the Publication shall end on the applicable Website Hosting Termination
    Date. Ziff Davis Media's obligation in Section 6(i) to include subscription
    offers for ZDNet newsletters within its subscription signups shall end on
    March 1, 2001.

9.  ZDNet will continue to include online subscription forms for each
    Publication on the Publication Website until the Website Hosting Termination
    Date for such Publication. In addition, ZDNet will distribute one mailing
    per month until the applicable Website Hosting Termination Date to the ZDNet
    announce list. Such mailing will promote subscription offers for any
    Publication still hosted by ZDNet on the date such announce mailing is
    distributed. Ziff Davis Media will create the content of the mailings,
    however, it will be subject to ZDNet's reasonable prior review and approval.
    Ziff Davis Media will pay to ZDNet $5.00 per net subscriber (both controlled
    and paid) generated as a result of such mailings. Net subscriptions for
    Publications with a paid circulation means subscriptions for which the
    subscriber actually pays and for Publications with controlled circulation
    means subscriptions for which the subscriber actually qualifies. Payment
    shall be made to ZDNet within thirty (30) days after the end of each
    calendar quarter (for example, on April 30, 2001 for the period through
    March 31, 2001) and ZDNet shall have the same rights of audit with respect
    the payments owed to it under this Paragraph 9 that are given to Ziff Davis
    Media under Section 5(iii) of the License Agreement. Ziff Davis Media will
    have the right to set the terms and rates of such subscription offers. The
    provisions of Sections 6(ii) and 6(iii) of the License Agreement will
    terminate on March 1, 2001 and neither party shall have any continuing
    obligations under such Sections from and after such date.

10. From and after March 1, 2001, the obligations of each party under Section 7
    of the License Agreement will terminate and such Section 7 will have no
    further force or effect.

11. Section 8(iii), Section 8(iv) and Section 17 of the License Agreement are
    hereby deleted in their entirety effective as of March 1, 2001 and neither
    party will have any further obligations thereunder.

12. Section 10(v) of the License Agreement is hereby modified such that the
    measure of the cap on Ziff Davis Media's liability for damages shall be the
    larger

                                      -7-
<PAGE>

    of (a) the amount of royalties paid to Ziff Davis Media in the contract year
    preceding the claim, and (b) $6.5 million (such larger amount, the
    "Liability Cap"). In addition, the Liability Cap shall not apply to Ziff
    Davis Media's liability for any willful breach of the License Agreement as
    amended by this Agreement.

13. From and after the date of this Agreement, Section 12 of the License
    Agreement shall be deleted and such Section 12 will have no further force or
    effect; provided, however, that the licenses granted to ZDNet under the
            --------  -------
    License Agreement (as amended by this Agreement) are personal to ZDNet and
    CNET, and may not be assigned by ZDNet or CNET except in connection with the
    sale or transfer of all or substantially all of their assets or businesses,
    or the merger into another entity, where the surviving entity agrees to be
    bound by the provisions of this Agreement, provided that this Agreement may
    not be assigned in whole or in part, including by operation of law, to
    International Data Group, Inc., CMP Media, Inc., United News & Media PLC, or
    Imagine Media, Inc., or any of their affiliates (defined for purposes of
    this paragraph as any entity which is controlled by, controls or is under
    common control with any of the named entities).

14. Section 18(i)(a) of the License Agreement shall be amended so that all
    notices to Ziff Davis Media will be sent in care of Ziff Davis Media, Inc.,
    28 East 28th Street, 14th floor, New York, New York 10016, Attention: Chief
    Executive Officer, with a copy sent to the same address to the attention of
    the company's General Counsel.


B.   MISCELLANEOUS

     1.  CNET and ZDNet will be jointly and severally liable for all
         obligations, including without limitation payment obligations, of ZDNet
         under the License Agreement and this Agreement.

     2.  Ziff Davis Media, on behalf of itself and its subsidiaries and
         affiliates, hereby waives any and all breaches of, defaults under, or
         failures to comply with the terms and conditions of, the License
         Agreement by ZDNet which have occurred on or before the date of this
         Agreement and each hereby releases each of CNET and ZDNet and their
         respective affiliates from liability with respect to such waived
         matters, including any claims arising out of, resulting from or
         relating to the Yahoo! Agreement prior to the date of this Agreement;
         provided, however, that such waiver and release is a one-time waiver
         --------  -------
         and release and will not waive or release future compliance with the
         terms of the License Agreement as amended by this Agreement (except as
         specified above with respect to the Yahoo!

                                      -8-
<PAGE>

    Agreement). This waiver is limited as specified and will not constitute
    a modification or amendment to any provision of the License Agreement.

3.  CNET and ZDNet, on behalf of themselves and their subsidiaries and
    affiliates, hereby waive any and all breaches of, defaults under, or
    failures to comply with the terms and conditions of, the License Agreement
    by Ziff Davis Media or Ziff Davis Publishing which have occurred on or
    before the date of this Agreement, and each hereby releases each of Ziff
    Davis Media and Ziff Davis Publishing and their respective affiliates from
    liability with respect to such waived matters, including any claims arising
    out of, resulting from or relating to any failure of Ziff Davis Media to
    provide or make available to ZDNet prior to or after the date of this
    Agreement, Content from the PC Expert Publication in France; provided,
                                                                 ---------
    however, that such waiver and release is a one-time waiver
    -------
    and release and will not waive or release future compliance with the terms
    of the License Agreement as amended by this Agreement (except as specified
    above with respect to the PC Expert Publication). This waiver is limited as
    specified and will not constitute a modification or amendment to any
    provision of the License Agreement.

4.  Except as modified by this Agreement, the License Agreement will continue in
    full force and effect in accordance with its terms. To the extent that this
    Agreement contains terms, conditions or agreements which are different from,
    in addition to or are inconsistent with the terms of the License Agreement,
    the terms of this Agreement will govern. This Agreement will be governed by
    and construed in accordance with the law of the State of New York applicable
    to agreements made and to be performed in New York. Each party agrees that
    any action or proceeding brought by the other during or after the term of
    this Agreement arising out of or related to this Agreement shall be brought
    in courts located in the State of New York. Each party irrevocably consents
    to the jurisdiction of the courts of the State of New York and of any
    Federal Court located in New York in connection with any action or
    proceeding brought during or after the term of this Agreement and arising
    out of or related to this Agreement and waives any objection to venue or any
    claim that the action is brought in an inconvenient forum. This Agreement
    may be executed in one or more counterparts and may be executed by facsimile
    signature.

5.  Except as may be required by law or the rules of any applicable securities
    exchange, no party to this Agreement shall make, nor permit its controlled
    affiliates to make any public statements about this Agreement or the License
    Agreement without the prior approval of the other party, which shall not be
    unreasonably withheld or delayed.

                                      -9-
<PAGE>

     Please have an authorized representative of ZDNet  and CNET sign below to
indicate your agreement with the foregoing.

                                      -10-
<PAGE>

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

                                    ZIFF DAVIS MEDIA INC.



                                    By: /s/ Thomas McGrade
                                       ---------------------
                                       Name:  Thomas McGrade
                                       Title: Senior Executive Vice President
                                              and Chief Operating Officer


                                    ZDNET, INC.



                                    By: /s/ Daniel Rosensweig
                                       ---------------------
                                      Name:  Daniel Rosensweig
                                      Title: Authorized Signatory

                                    CNET Networks, Inc.



                                    By: /s/ Daniel Rosensweig
                                       ---------------------
                                       Name:  Daniel Rosensweig
                                       Title: Authorized Signatory

                                      -11-
<PAGE>

                                   Schedule 1
                                   ----------

                                 See Attachment

                                      -12-