It's good to report crime.
Frank is buying a candy bar at a grocery store when he notices someone shoplifting.
Frank wants to get out of the store quickly.
Frank tells a clerk at the store what he saw and then uses the self-checkout to avoid delays caused by the store personal dealing with the shoplifter.
Frank ignores the shoplifter, so he can check out and leave the store more quickly.
The store owner thanks Frank for his good work and rewards him with a small gift card to the store.
The store owner loses money and has to increase the store's prices to compensate, resulting in Frank paying more when he goes to buy candy.