Why do some cities have a marked preference for specific drinks? (Postdlf, Wikimedia Commons)

Data from millions of Starbucks transactions around the country revealed (unsurprisingly) that the most popular drink by volume sold is regular brewed coffee, with lattes coming in a distant second.

But certain cities also showed an unusual affinity for certain drinks. Seattle coffee drinkers are likelier than anyone else to add an extra shot of espresso. San Franciscans really like soy lattes. Los Angelenos enjoy Frappuccinos more than anyone else, as do people in San Antonio, Texas. 

Just as a Mason-Dixon line divides the U.S. into northern and southern halves, a hot-cold axis also exists; Florida, New Mexico, Texas, Arizona, Oklahoma, Hawaii, and Southern California (given the differences between north and south, SoCal might as well be its own state) are the only states who order more iced than hot coffee.