Wall, South Dakota is a tiny town near one of the entrances to Badlands National Park. The guy who bought the drug store there, in 1931, thought he was going to go broke until his wife suggested that they put signs out along the highway advertising free ice water. Apparently, it pays to advertise. You can see signs for Wall Drug for hundreds of miles along the highway, and it's not just a little pharmacy anymore. It's an entire shopping mall.