system: You are a contract-analysis assistant performing a span-extraction task. You are given an excerpt from a commercial contract and the name of a clause type to locate within it.

Return the exact text of the requested clause, copied verbatim from the excerpt — identical wording and punctuation, with no paraphrasing, summarising, explanation, or added commentary.

The excerpt is one window of a much longer contract and often will not contain the requested clause. If the requested clause does not appear in this excerpt, respond with exactly: Not found.

Output only the extracted clause text, or the exact string `Not found.` — nothing else.

user: Contract excerpt:
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1 Exhibit 10.16 CONFIDENTIAL Portions of this Exhibit have been omitted pursuant to a request for confidential treatment. The omitted portions, marked by [****], have been separately filed with the Commission. SPONSORSHIP AGREEMENT This agreement ("Agreement") is entered into as of the 23rd day of September, 1997 ("Effective Date"), by and between Excite, Inc., a California corporation, located at 555 Broadway, Redwood City, California 94063 ("Excite"), and N2K Inc., a Pennsylvania corporation, located at 55 Broad Street, 26th Floor, New York, New York, 10004 ("Sponsor"). RECITALS A. Excite maintains a site on the Internet at http://www.excite.com (the "Excite Site") and owns and/or manages related Web Sites worldwide (collectively, the "Excite Network") which, among other things, allow users to search for and access content and other sites on the Internet. B. Excite also maintains and/or manages certain Web pages which may be delivered to users via email, desktop "channels" or Internet "push" technologies (collectively, "Broadcast Pages") which may incorporate content supplied to Excite by third parties for the purpose of providing value to Excite users and providing access to the content, products and/or services of such third parties. C. Sponsor is in the business of distributing certain online retail music merchandise and related content and maintains a Web site at http://www.musicblvd.com (the "Sponsor Site") and other Web sites through which it makes this merchandise and this content available to its users. D. Sponsor wishes to be the exclusive retail store music sponsor of the Excite Site and the Excite Broadcast Pages, to distribute its music-related content through the Excite Site and the Excite Broadcast Pages and to promote its online retail music merchandise business to Excite.com users. Therefore, the parties agree as follows: 1. EXCLUSIVITY, TERM AND RIGHT OF FIRST REFUSAL a) Sponsor will be the exclusive retail music store sponsor of the Excite Site and the Excite Broadcast Pages. Excite will not permit the display of advertising banners, promotional buttons, promotional links or other promotional materials for any retail sale of Music Products on the Excite Site, except those Music Products offered by Sponsor, nor advertising by any other Retail Music Store. "Retail Music Store" shall mean any entity which is primarily engaged in the sale of Music Products at retail to consumers. "Music Products" 2 CONFIDENTIAL shall mean pre-recorded music hard goods, digitally distributed music (except live and/or cybercast events), music books (to the extent this Agreement does not conflict with Excite's existing agreement with Amazon.com), music-related t-shirts and apparel, and music videos (except live and/or cybercast events). Notwithstanding the foregoing, Excite may make available opportunities on the Excite Site to purchase Music Products from parties other than Sponsor if such Music Products are not available from Sponsor so long as, prior to entering into arrangements to make available opportunities to purchase Music Products from parties other than Sponsor, Excite notifies Sponsor of its interest in the Music Products and gives Sponsor thirty (30) days to make the desired Music Products available through the Sponsor Site. Excite and Sponsor acknowledge that certain market opportunities may arise in which the desired Music Products must be made available on less than thirty (30) days advance notice and will work together in good faith to maximize those opportunities. In no event will Excite enter into arrangements to make available opportunities to purchase Music Products from parties other than Sponsor that would prevent Sponsor from being the exclusive source of such Music Products on the Excite Site once the Music Products become available through Sponsor. b) The term of this Agreement will begin on the Effective Date and will end on the second (2nd) anniversary of the Commencement Date. The "Commencement Date" means the date on which Excite commences delivery of Impressions (defined below). The parties anticipate the Commencement Date will be on or about October 15, 1997. c) The parties' existing agreements regarding sponsorship of the WebCrawler Web site (http://webcrawler.com) and all of the existing advertising buys on the Excite Network will be terminated as of the Commencement Date. Excite will credit Sponsor in an amount equal to [****]. This credit will be applied to reduce the first year exclusivity fee described in Section 7(b) and will be reflected in a reduction of Sponsor's December 31, 1997 payment to Excite described in Section 7(e). d) Excite will offer Sponsor the right of first refusal to negotiate with Excite for renewal of this sponsorship. 2 3 CONFIDENTIAL i) Excite will not propose, solicit or negotiate offers from entities other than Sponsor for any
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Extract the exact clause related to "Notice Period To Terminate Renewal" from the excerpt above.