Money is first as well stated by many posters, but there is a larger variable that is coming on board and that is the new revamped "playoff" system in football. The details on qualifying for the top 4 spots (and eventually increased to the top 8) will drive the expansion of conferences eventually building to 16 team members "super conferences" to better enhance their chance of getting into the big dance for football. We will have to wait for the specific details of the playoff system to be released, but soon you will see a "feeding frenzy" of major conferences trying to establish themselves at the top of the NCAA food chain. The ACC will soon become an irrelevant "bottom feeder" in football and I believe the ACC has been planning for this scenario for a couple of years.