Just last week as I was driving through Wyoming I began to see the signs. After going through Deadwood, and on to I-90, they became more frequent. For about 50 miles before the place there are signs on the highway, most are no more than 1/4 mile apart. By the time you get there, you simply cannot drive by. One of these days I want to find out whether Wall Drug or Pedro's South of the Border is winning the sign race. Wall Drug had an advertisement in the London Underground, but Pedro also has signs for 100 miles afterwards encouraging you to turn around and head back.
Wall Drug was founded in 1931 by Ted Hustead and his wife Dorothy. They struggled for about 5 years with little business. Then, Dorothy came up with an idea to get people on the nearby major route through South Dakota to stop by. Free ice water. They made some signs and put them out on the highway, and people flooded the place. Through the years, it's just sort of grown from there. It's not really a Drug Store anymore, they do have a small selection of aspirin and other over the counter drugs, but you'd hardly guess the place would be considered a drug store.
Currently, Wall Drug is run by Teddy Hustead, grandson of founder Ted Hustead. The store covers 72,000 square feet and they sell clothing, Black Hills gold, food, jewelry, and other tourist crap. Of course, there is free ice water. The coffee is still 5 cents, and there is free coffee and donuts to Vietnam vets and newlyweds. Of course, you can also tour and shop Wall Drug on the internet at www.walldrug.com if you don't want to make the drive. But, if you ever find yourself driving in the area, stop by and get your free ice water.