As a kid I used to have a lemonade stand. The sign said, "All you can drink for a dime." So some kid would come up, plunk down his dime, drink a glass, and say, "Refill it."

I'd say, "That'll be another dime."

"How come? Your sign says -- All you can drink for a dime!"

"Well, you had a glass didn't you?"

"Yeah."

"That's all you can drink for a dime."