Effect on restaurant tipping of a helpful message written on the back of customers' checks

Research has shown that servers can increase their tip percentages by writi ng "Thank you" or by drawing a happy face on the backs of customers' checks . In the current study, a third approach of this type was tested. An experi ment was conducted in which a female server either did or did not write a h elpful message about an upcoming dinner special on the backs of checks befo re delivering them to customers. It was predicted that adding the helpful m essage would increase tip percentages because of reciprocity, in which cust omers would tend to respond to the server's "tip" with an increased tip of their own. Results were consistent with this prediction: Mean tip percentag es increased from about 17% to 20%.