Every few years I post this map. Anyone have good explanations for some of the patterns? (e.g., what’s going on around St. Louis and Milwaukee?)

Update: A Google Maps based survey is up. You can vote, so please do!

Every few years I post this map. Anyone have good explanations for some of the patterns? (e.g., what’s going on around St. Louis and Milwaukee?) Larger fine-grained version below the fold. I would say that one inference that you could make is that the fact that “Soda” has penetrated the territory of “non-Soda” through either migration or cultural emulation. The concentrations in south Florida, northern Virginia and the Research Triangle are pretty good evidence of this, as well as Denver.