If your site is very targeted towards specific colleges, make your money from offline adverts. Call up the local pubs, nightclubs, live music venues, or whatever and get in touch with someone in promotions. Call up the skate shops, head shops, whatever else is in your area that might connect. Present them with your traffic stats and demographics, and give them a good pitch as to why the should advertise their events with you. See what's being pitched on the local radio stations with the college listeners...
