I just happened to come across this on another forum and I found it interesting.
Going back to Mike's inquisition about popularity of the NBA, these are the number of "Facebook Followers" for different sports...
Vancouver 2010 Olympics: 1,209,379
WWE: 757,845 (obviously not a real sport, but interesting nonetheless)
Women's Tennis Association: 223,986
Penn State football: 170,737
English Premier League: 156,706
PGA Tour: 137,406
ATP tennis: 136,653
NHRA drag racing: 91,650
I am actually not shocked to see UFC so high on the list, mainly because most of the fans of MMA have to get their content online, but the NBA still is still above them by almost 1 million people.
Also, it's only fair to point out that when talking about the major sports leagues, those are the numbers ONLY for the LEAGUE pages, those numbers do not reflect the number of people following each individual team. Heck, I don't follow the NBA on Facebook, but I do follow the Chicago Bulls and the Phoenix Suns, so it's safe to say the numbers would be higher for NBA, NFL, MLB, and NHL.