The National Football League is one of the most popular sports in America with some incredibly devoted fans. At Facebook we have about 35 million account holders in the United States who have Liked a page for one of the 32 teams in the league, representing one of the most comprehensive samples of sports fanship ever collected. Put another way, more than 1 in 10 Americans have declared their support for an NFL team on Facebook.
Winning Fans Over
Are people fans of a team because of their friends, their hometown, or just because that team enjoys some success? It certainly looks like winning helps. We looked at how many users clicked "Like" for each team's page on each day throughout the season. On any given day during the season a team either doesn't play, loses, or wins (we'll ignore ties). Because playoff teams get so much more attention, we'll break out separate categories for games during the playoffs.
Lots more at the link, very interesting data. Basically, Cowboys and Steelers are the most common fans. If you are a Texans fan, you are mostly likely to have Cowboys, Saints, Steelers, Pats and Packers fans as friends on Facebook.