Coca-Cola began to be sold in glass bottles in the last years of the 19th century -for five cents, the same price the fountain servings had been for years. Those bottled Cokes sold for a nickel until 1959! Oh, it wasn't because the company just wanted to keep the price all that time, but circumstances made raising the price difficult.
The Coca-Cola vending machines were built to take a single coin: a nickel.
Levy says the folks at Coca-Cola thought about converting the vending machines to take a dime. But doubling the price was too much. They wanted something in between.
So they asked the U.S. Treasury to issue a 7.5-cent coin. At one point, the head of Coca-Cola asked President Eisenhower for help. (They were hunting buddies.) No luck.
There were other factors involved, which you can read about at WEKU. Link -via Metafilter