From MIT’s Technology Review, a brief post about an anecdotal study by Facebook that has color-coded the nation by county according to NFL team:
Thirty-five million U.S. Facebook users have “liked” the page of at least one of the NFL’s 32 teams. Combine that with location data and you’ve got, as Facebook says, “one of the most comprehensive samples of sports fanship ever collected.”
Unsurprisingly, most counties devoted to given team are concentrated in that team’s region of the country. The fanbases of few teams, though, are apparently not as bound by geography. The Dallas Cowboys are often referred to “America’s team,” and the data do indicate that the team’s fanbase covers an impressively large area of the country, stretching from Virginia to California, and pro-Cowboy counties appear in nearly every region. The Pittsburgh Steelers fan footprint is also fairly large and dispersed. Tim Tebow’s New York Jets, meanwhile, are the most popular team in only one county on Long Island.
They whittled down the numbers to just those pertaining to your two Super Bowl teams, which is strikingly in favor of San Francisco, and looks like this:
The original Facebook post, which has some other interesting information, and ways to look at the numbers, is here.