http://www.goal.com/en-gb/news/3353/mls ... or-lack-of
Don't forget that soccer — as they call football there — is the most popular game with the youth," Blatter said. "It's not American football or baseball; it is soccer. But there is no very strong professional league. They only have MLS, they do not have these professional leagues that are recognised by the American society.
"I thought it was a question of time when they had the World Cup in 1994, but now we are in 2012 - it’s been 18 years - it should have been done now. But they are still struggling."
Statistics show, however, that MLS is ranked third in terms of attendance at American sporting events, with an average of 18,807 fans per game.