Advertisers are thinking beyond the large audiences that watch the NCAA men's basketball tournament on television and webcasts. They want to encourage support via virtual campuses. Companies like Pontiac and Wachovia have decided to supplement their television advertising campaigns by attempting to tap into schools via the official websites of their athletic departments. They have targeted the sites of the University of North Carolina and Michigan State, for example. According to Chris Hornberger, advertising manager for General Motors Corp.'s Pontiac, visitors are checking these websites for information directly related to the school. Larger marketing companies are always interested in reaching college students, who have tended to be an elusive group. They see the basketball championships as a way to target alumni for the 65 teams chosen to play in the tournament as well. These graduates generally have lots of money and a strong emotional attachment to their schools. Colleges and universities are aided in their efforts to find marketers by firms that put the smaller department sites into a network, operate the sites, and sell ads. CSTV Networks, a unit of CBS Corp.'s cable channel, is the leader in this industry, hosting 250 official college websites, including 38 of those associated with the participants in March Madness. The other large player in the field is XOS Technologies Inc., which hosts sites for 100 colleges.