Sometimes, we can see that hotels or restaurants providing buffet grant a special offer to those diners who can finish their meal and pay the bill earlier. The hotel or restaurant owners will state clearly in their menu that a certain discount will be offered if diners can pay their bills before a specified time.

The purpose of granting this kind of special offer is to cut the enforcing cost. Though the hotel or restaurant owner earn less due to the special offer, he can actually save a greater amount of enforcing cost. As diners tend to finish their meal in a shorter time, in order to enjoy the special offer, the hotel or restaurant can cut the cost of hiring more waiters to offer towels and to ask diners whether they have finished their meal, which would otherwise be incurred by the restaurant owners in enforcing the rights to tables and seats.