Play "Bean" before the game starts and at least once every quarter. That is something cool - do it more.
To try to keep students longer, at the end of the 3rd quarter, do the "Blue Man Group" tissue paper pull down through the student section. If you've never seen, it's pretty cool and the students would love it and it would be unique. At the top of the section, you would mount LARGE rolls of paper (red, white and blue). You get those rolls spinning and the students pass it down the stadium. It gathers into a Hugh mound of paper and color, cascading down the stands. When it gets to the bottom, have the cheerleaders gather it up to be recycled. Cheerleaders could be the ones to get the rolls started. You need a lot of rolls and volume. Maybe it would be $1000??? But it would be unique!!! and maybe keep our students for it. If the student section got light, every kid and some adults would run to be in it.