On April 28, 1997, Ticketmaster sued Microsoft for including a link to the Ticketmaster home page on Microsoft's Seattle Sidewalk entertainment site. Ticketmaster argues that a formal license agreement is required before anyone can link to its site. Ticketmaster had been negotiating such a license with Microsoft, but negotiations broke down. Instead, Ticketmaster entered into an agreement with CitySearch, a competitor of Microsoft's sidewalk site.
Ticketmaster bases its lawsuit on a claim that the use of Ticketmaster's name and trademark in the unauthorized link dilutes the value of Ticketmaster's trademark and sponsorships with other companies. This claim apparently rests on the legal theory that the inclusion of the Ticketmaster link on Microsoft's page constitutes trademark dilution under the 1995 Federal Trademark Dilution Act.
Ticketmaster also claims that Microsoft is providing incorrect information on the payment methods accepted by Ticketmaster. The Seattle Sidewalk site states that American Express, Visa, MasterCard, and personal checks are accepted by Ticketmaster. It is interesting to note that Visa is one of the advertisers on Microsoft's Seattle Sidewalk site, while a Master card ads is prominently placed on the Ticketmaster site.