Rototiller Rental

Coming from a big city, my friend David wasn't prepared for the approach rural Maine businessmen take toward their customers. Shortly after David moved there, he rented a rototiller. The store owner showed him how it worked and explained that the charge was not based on how many hours he had it out, but rather how long it was actually used. Looking over the tiller for some kind of meter, David asked, "How will you know how long I've used it?"

With a puzzled look, the owner simply said, "You tell me."