Utah was added for its TV market and nothing else. TV markets are only valuable when you have a conference network.
Brand names are always important because they add prestige to a conference.

Luckily for the Big 12 BYU is both a brand name and a huge Digital TV market. The next big "Thing" in media viewing is digital streaming and BYU brings a lot to the table on that front. The Big 12 has already added a Big 12 Digital Network and that gives us every indication BYU is very valuable to the Big 12's future.

Because the traditional TV Network is not a possibility, the only way the Big 12 can generate new streams of revenue is thru adding teams to their conference and giving them incremental portions of the revenue generated by the conference and staring a digital media network.

If the Big 12 is bound and determined to add schools to there conference and their media partners are contractually obligated to pay them pro rata per school then BYU is at the top of ESPN/FOX's list.