Pretty cool map:

http://img509.imageshack.us/img509/8382/updatednewmapyu7.jpg

The Mets have the smallest fan base by area

I don't know what that's a map of but it doesn't represent fan base. Most of Florida doesn't give a flying damn about either the Rays or Marlins.

I love maps, and this is an interesting one, with a few surprises. For example, I didn't realize the Cincinnati Reds had such a large fan base (at least compared to Cleveland). And I think the Yankees, despite being hated by many, probably should occupy a bigger chunk of the map than just New York state...in fact, further to Joe's comment, aren't there a lot of transplanted New Yawkers down in Florida? There are probably more Yankees fans there than Marlins or (Devil) Rays fans. And the Canadian side of the border should show support for the Blue Jays throughout Canada, not just in southern Ontario (although admittedly, baseball is less popular in Canada than in the U.S.) There are pockets of support for U.S.-based teams here as well, that are not showing on the map. For example, the Detroit Tigers (Windsor-London-SW Ontario), Seattle Mariners (Vancouver-Victoria, and to a lesser extent elsewhere in BC and Alberta), Minnesota Twins (Winnipeg for geographical reasons, but also in BC due to the presence of Justin Morneau), Boston Red Sox (mainly the Atlantic provinces, but in other parts of the country too), and the Yankees (not a huge number of diehard fans, but spread out across Canada, mainly because they are the most famous team in baseball).

otoh, plus-sized Midwesterners mean there aren't as many Cardinal fans in that large territory as you think (and the D-Backs have a lot of rooters that are cactuses)...

This "map" strikes me as utterly unscientific guesswork.

It's marketing for Nike, not brilliant cartography. I just thought it was fun to look at it and might provoke some discussion.

Now I notice the Nike symbol.