While media markets are absolutely part of the analysis, the ability to deliver ratings and value are more important than the geography of the media market in which the school is situated.
This is actually why I think BYU and SDSU are an intriguing pair - because BYU helps to deliver the California market. BYU has California fans and alumni, of course -and that helps, but it gives the Big 12 the opportunity to schedule later kickoff times with the Pacific and Mountain time zones added to the TV inventory. For instance, BYU-Kansas St. at 7:30pm Pacific could steal ratings from most MWC games and many PAC 12 matchups.