Bait-and-switch

Bait-and-switch is a form of fraud used in retail sales but also employed in other contexts. First, customers are "baited" by merchants' advertising products or services at a low price, but then, when they visit the store, those customers discover that the advertised goods are not available and are pressured by salespeople to purchase similar but higher-priced ones ("switching").

Bait-and-switch techniques have a long and widespread history as a part of commercial culture. Many variations on the bait-and-switch appear, for example, in China's earliest book of stories about fraud, Zhang Yingyu's The Book of Swindles (c. 1617).