With such close proximity to Chelsea i could see that. But do most Americans who like football already have a team?
My friends, even the most casual, would all give you an answer to an NFL team they prefer. One of my mates has always like the Seahawks as they constantly failed to win the SB. He didn't know what to think last February
No doubt many Americans have a team already, but I think there are quite a few ripe for a team that have never had a team. Until 2-3 years ago it wasn't that easy to watch a match, outside of the random United-Chelsea match that a major network would have on Saturday morning mid-winter after the college football games were finished and before college basketball becomes interesting.
Now, especially with NBC, you can watch most teams on TV or at least through a dodgy website. There are quite a few reasons that your average American can be drawn to a team, and while some of them are less than perfect reasons, once you get pulled in its hard to turn away. My wife is a Florida graduate and die-hard gator, but she hasn't even watched a game this season. To be fair, they're horrible under Muschamp. But still, every weekend she asks when we're going to watch Everton.
Back on topic, no small number of Americans (allegedly, presumably) are drawn to Tottenham as the Arsenal alternative. Not simply because they like Spurs, at least not initially, but because they like being Arsenal's rival. (Granted, there are a large number of Arsenal fans in America, so don't let me get carried away with the example...). I'm not sure this would work for all teams, like Villa, but Fulham
could do well picking up support among Americans.