Definitely interesting to see, though obviously there are so many flaws with making conclusions about this map.
The author even called the Cowgirls America's team because of that, Even though there's probably more people in the tristate area alone than that entire blob combined (or something close)
For starters, you have to be on Facebook, then you have to "like" your team.
So if I were to draw conclusions about the Jets vs Giants fanbase, I'd say more Giants fans were dorks on facebook than Jets fans.
(Yes I'm on facebook, and yes I like the Jets