Will that be a pop, soda, or coke?

Having spent most of the summers of my formative years in New Jersey, I already knew that certain American cultures called it "soda" while most Canadians call it "pop". What I did not know is that some parts of the States call it "coke", whether it's cola or not. The map above gives an idea what parts of North America primarily call it what (green=pop; blue=soda; red=coke). I have a problem with the study of course, because I think a lot of people ask for a coke when in fact that's what they really want specifically - a Coke (or at the very least - a cola).