Contracts don't necessarily need a signature to be valid. If you order food at a restaurant, there is an implied contract that you will pay for the meal. Howe

Contracts don't necessarily need a signature to be valid. If you order food at a restaurant, there is an implied contract that you will pay for the meal. However, this amount is almost always stated in the menu, so it isn't arbitrary. In fact, in each of the above cases, the amount you pay is almost never arbitrary, but based on usage or a preset price.