Here's what you do to keep fans in the stands - run some promotion similar to the Buffalo Wild Wings at the basketball games, but instead of using ticket stubs, hand out coupons at the end of the game to fans as they're leaving the stadium. And it should be something that won't get the fans booing a win because we didn't go for another score. Maybe something like forcing three turnovers.
My local minor league baseball team has a promotion where if a certain player on the opposing team strikes out three times, everyone gets free pizza from a local pizza place. But they don't use stubs. They give you coupons as you're leaving. It keeps fans actively engaged and in their seats until the end of the game. If you leave early, you don't get pizza. Then again, there was a game a few years ago where said player was standing on deck in the top of the ninth with two strikeouts already and the batter hit into a double play to end the game. The fans weren't happy. Fortunately, there are no double plays in football.