Descriptive norms can be seen operating when street performers, cocktail lounge pianists, coat-check attendants, baristas, and others who work for tips “seed” their tip containers with bills in the amounts they hope their customers will contribute. The idea is that if a pianist’s tip jar already holds a few five-dollar bills, and maybe even a ten, listeners are led to assume that these are normal tip amounts and might thus be more likely to contribute similar amounts themselves.