Influence: The Psychology of Persuasion

by Robert B. Cialdini

Consider how this simple insight made one man a multimillionaire. His name was Sylvan Goldman and, after acquiring several small grocery stores in 1934, he noticed his customers stopped buying when their handheld shopping baskets got too heavy. This inspired him to invent the shopping cart, which in its earliest form was a folding chair equipped with wheels and a pair of heavy metal baskets. The contraption was so unfamiliar-looking that, at first, none of Goldman’s customers used one—even after he built a more-than-adequate supply, placed several in a prominent place in the store, and erected signs describing their uses and benefits. Frustrated and about to give up, he tried one more idea to reduce his customers’ uncertainty, one based on social proof. He hired shoppers to wheel the carts through the store. His true customers soon began following suit, his invention swept the nation, and he died a wealthy man with an estate of over $400 million.