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:
"""
EXHIBIT 10.8 [Certain confidential information has been omitted from this Exhibit 10.8 ------------ pursuant to a confidential treatment request filed with the Securities and Exchange Commission. The omitted information is indicated by the symbol "***" at each place in this Exhibit 10.8 where the omitted information appeared in the ------------ original.] CO-BRANDING AGREEMENT --------------------- This Co-Branding Agreement (this "Agreement") dated March 15, 2000 (the "Effective Date") is entered into between VerticalNet, Inc., a Pennsylvania corporation having a principal place of business at 700 Dresher Road, Suite 100, Horsham, Pennsylvania, 19044 ("VerticalNet"), and LeadersOnline, Inc. a Delaware corporation having a principal place of business at 18401 Von Karman Avenue, Suite 500, Irvine, California, 92612 "(LeadersOnline") (each a "Party" and together the "Parties"). BACKGROUND WHEREAS, VerticalNet owns and operates a series of Online Communities (as defined below) that are accessible via the World Wide Web, each of which is designed to be an online gathering place for businesses of a certain type or within a certain industry; and WHEREAS, LeadersOnline desires to advertise its job placement services (the "LeadersOnline Services") on certain of VerticalNet's Online Communities through banner ads, newsletters and employer spotlights, to access VerticalNet's proprietary resume bank and to display and maintain a Link (as defined below) from the LeadersOnline Site (as defined below) to a VerticalNet Site (as defined below) to enable users of the LeadersOnline Site to access and utilize the VerticalNet Online Communities; and WHEREAS, VerticalNet desires to permit LeadersOnline to advertise the LeadersOnline Services on certain of VerticalNet's Online Communities through banner ads, newsletters and employer spotlights, to allow LeadersOnline access to VerticalNet's proprietary resume bank and to create a Link from the LeadersOnline Site to a VerticalNet Site to enable users of the LeadersOnline Site to access and utilize the VerticalNet Online Communities. NOW, THEREFORE, in consideration of the mutual covenants herein, and intending to be legally bound hereby, VerticalNet and LeadersOnline agree as follows: I. DEFINITIONS 1.1. Affiliate shall mean, when used with reference to a Party, any individual or entity directly or indirectly controlling, controlled by or under common control with such Party. For purposes of this definition, "control" means the direct or indirect ownership of at least 50% of the outstanding voting power of a Party, or the right to control the policy decisions of such Party. 1.2. Banner shall mean a graphical image advertising a Party's Site that is posted on the other Party's Site in an area designated by the Party controlling the Site on which the image is posted, and containing a Link to the Site of the Party which purchased the Banner. 1.3. Career Center shall mean that area of the VerticalNet Online Communities designated by VerticalNet in which VerticalNet offers various employment related services to Users of the VerticalNet Sites, including resume posting, career information and Employer Spotlights. 1 1.4. Confidential Information shall mean, subject to the provisions of Section 9.2 [Exclusions], all proprietary and confidential information of a Party, including, without limitation, trade secrets, technical information, business information, sales information, customer and potential customer lists and identities, product sales plans, sublicense agreements, inventions, developments, discoveries, software, know-how, methods, techniques, formulae, data, processes and other proprietary ideas, whether or not protectable under patent, trademark, copyright or other areas of law, that the other Party has access to or receives. For purposes of this Agreement, this Agreement shall be considered Confidential Information. 1.5. Employer Spotlight shall mean a feature on the VeticialNet Sites containing company listings that Link to full-page company descriptions of employers actively recruiting candidates to fill open positions within their companies that is framed by VerticalNet Proprietary Features. 1.6. Home Page shall mean the first page presented when a User selects a Site or presence on the World Wide Web. 1.7. HR Site shall mean the VerticalNet Site located on the World Wide Web at HRHub.com, or any successor Sites thereto. 1.8. Intellectual Property shall mean any and all trade secrets, patents, copyrights, trademarks, service marks, URLs, trade dress, brand features, know- how and similar rights of any type under the laws of any applicable governmental authority, including, without limitation, all applications and registrations relating to any of the foregoing. 1.9. Intellectual Property Rights shall mean all rights in and to Intellectual Property, including, without limitation, all patent rights, copyrights, trademarks, service marks, know-how and trade secrets. 1.10. LeadersOnline Mark shall mean any trademark, service mark, trade name, domain name, design or logo of LeadersOnline or its Affiliates. 1.11. LeadersOnline Site shall mean the Site
"""

Extract the exact clause related to "Effective Date" from the excerpt above.

assistant: March 15, 2000