Au Bon Pain uses mystery customers to evaluate the performance of its restaurants and their employees. To establish a direct relationship between performance and rewards, managers whose employees score 100 percent in all twelve of the categories that are evaluated receive an on-the-spot bonus of twenty Club Excellence Dollars-dubbed CDs. These dollars can be traded for items in a company catalog. Most items are in the $10-$70 range and include such things as Au Bon Pain sunglasses and portable cassette players. In addition, winners' names are posted on the store's bulletin board next to a list of the criteria for the program. All winners receive personal letters congratulations from company officials. Thus, it's clear whether Au Bon pain