Expand MLB baseball out of the 26 markets that it is currently played in. And what I mean is MLB seems to have forgotten about the next 30 markets.
The first thing I would do is have each MLB team play one series a year in an AAA Ballpark. Reward the AAA fan base for supporting the parent club and following those players up to the majors. Continue that connection.
For scheduling purposes this might be only possible for 15 teams to be able to be the home teams. But let the visitor teams make sure they get the rotation the following year.
Schedule low attendance series like when the Royals come to town. Kansas City fans living in the Bay area wont like this. But the benefits of the Rays playing a series in Durham will outweigh the upset fans.
Imagine the Cardinals playing a series in Memphis. Or the Cubs playing a series in Des Moines. Yankees in Scranton...etc.
Make this an event for every other year.