SOUTH DAKOTA: Wall Drug
This blatant tourist trap makes over $10 million a year, but how they do it is a mystery. The drugstore turned makeshift mall became famous for offering free ice water back in 1931, and doesn't charge for attractions such as their snake pit and giant road side sculptures (see the dino, above). They do reel in tourists and road trippers with over 300 billboards throughout the state, though.
Nice job proofreading!