[TownGuy]

The MLS is not necessarily more popular in certain cities if it is the favourite of more people. For instance my "favourite" team would be the Leafs, but I also follow the Jays and Raptors. I do not follow TFC at all but that survey doesn't take that into account. For Dallas more people might be following the Stars than the MLS club even though it is not their favourite team.

That would make sense IMO because the MLS is kind of counter-culture. In Toronto for instance MLS fans tend to be the most hostile to the other sports. They like soccer, and maybe basketball, but are passe to the typical North American sports. Basically they are very passionate about one league and don't care about the rest. Your typical North American sports fan is more likely to follow all of the Big 4, one is their favourite sure, but they still follow all of them.