It is as simple as that. With so much to compete with, if BYU really has a good marketing team (IMG which I think is poor), they will make tailgating a huge focus. We are talking Mormons with lots of big families. Make the games an event families want to be at. Even if families choose to go all day to 1 or 2 of the games it will raise attendance and excitement.
Coaches need to get out more and do breakfast or other types of events in the community leading up to the games. The more marketing that can be done around "community" the more successful it will be.