A few links of note from the Tampa Bay Business Journal:
According to a syndicated article in the Tampa Bay Business Journal, Tampa Bay is scheduled to break the 3 million mark in total population at some point in 2017. The Tampa-St Pete- Clearwater area is expected to grow 1.2% and near 3.07 million by year’s end.
According to Wikipedia, Tampa-St Pete-Clearwater is the 18th largest metro area in the US. Even with the gain beyond the 3 million mark, the area will still trail San Diego’s 3.3 million residents.
Assuming again that 50% of people are baseball fans, we can then assume 1.5 million baseball fans in Tampa Bay. If 50% of them are Rays fans, there will be 750,000 Rays fans in Tampa Bay. Likewise, if 15% of fans are Yankees fans, then 225,000 Tampa Bay residents will be pulling for the Yankees.
An increase in people could increase attendance or it could congest the roads so badly that fewer people travel to downtown St Pete to go to a Rays game. It could increase the workforce or it could be a drain on our social systems.
Tampa Bay is definitely a growing region. One with enough people and enough income to support Major League Baseball.