I used to never miss half-time. However, the band/halftime show has become boring, and the product on the field doesn't win many games anymore. When they do, it's against boring teams that we expected to win against anyways. The stadium doesn't sell beer and the whole music/environment just isn't what it used to be. So now, the third quarter has usually started by the time I'm back to my seat.
Change those things and the people will stay inside the stadium for half time.