Many services are delivered to a (large) number of customers simultaneously within a confined zone (e.g., restaurants, resorts, trains, and airplanes). Under unexpected high demand, customers experience discomfort from two major sources: (a) the sardine effect that arises when too many customers...

Major retailers in the USA offer Money Back Guarantees (MBGs) under which they return money to dissatisfied customers. Some of these retailers also offer Low price Guarantees (LPGs) under which they promise to refund price differences if buyers find a lower price after purchase. Some researchers...