The Web site www.tipthepizzaguy.com suggests the following: 15% for normal service, with a $2 minimum; 20% for excellent service; 10% or less for poor service; at least 10% for orders of $50 or more. Don't assume a delivery charge, if there is one, goes to the pizza deliverer. Ask the person who takes your order.

CNN/Money: How much to tip

money.cnn.com/pf/features/lists/tipping/