Make sure to replace them if they get torn down or stolen. That keeps the posters from blending into the mass of posters covering the walls on every campus. Try to arrange an advance telephone interview or story a few days before the show. Try to get the show reviewed for the next issue. Make sure that the campus radio station has the Artist's CDs, and encourage them to play them.
Nothing draws a crowd like airplay.
Try to arrange an on-air interview, either live, taped, or over the phone. If you don't have a campus station, try to work with a popular local station. They are sometimes sympathetic to the college audience. List all upcoming events, and have active links from your page to the performer's page. That way, students can log on and check out the acts before the show.