The NFL is the only major sport with a sense of parity--no big market bias, as exists in MLB and the NBA. The key is a hard salary cap, and non-guaranteed contracts. The players don't like this, and the TV people don't, either. They want the big markets to dominate, to max out their advertising revenues. You even see that in the NFL, where the two NY teams, the Giants and the Jets, have been showcased in almost every network night game this season.
In the NBA, Stern is fighting hard to keep NY and LA from dominating--but he also has to consider TV interests--which want the big markets to dominate. In MLB, Pujols followed the money--to LA--where the Angels will get $100 mil more TV revenue per year for the next 20 years from a new Fox contract. That paid for Wilson and Pujols. TV dominates.