You may need to rethink your traditional event days and times. If students no longer attend your Friday night programs, maybe you need to present them on a week night instead. If you do daytime shows, go to your Registrar's Office and find out what days have the most students. Find out the peak class hours, too. You may find, for example, that Wednesdays have the most students in the 10 am class and that the second highest peak is the 1 pm class.
Television can be a force on campus.
But don't forget the concept of counterprogramming. Maybe students leave because there's nothing to do. But if you try to break those patterns, be prepared for the long-haul. It may take months, or even years, of counterprogramming before the students stop going to Billy's Pub or going home on weekends and attend your events. It ranges from completely automated computer simulations to live performers.