Researchers have tested many persuasion strategies that are effective in selling products and changing people’s attitude, ideas, and behaviors. One effective strategy is the foot-in-the-door technique. Using the foot-in-the-door technique, the persuader gets a person to agree to a small favor or to buy a small item, only to later request a larger favor or purchase of a bigger item. The foot-in-the-door technique was demonstrated in a study by Freedman and Fraser in the 1960s in which participants who agreed to post a small sign in their yard or sign a petition were more likely to agree to put a large sign in their yard than people who declined the first request. Research on this technique also illustrates the principle of consistency: Our past behavior often directs our future behavior, and we have a desire to maintain consistency once we have committed to a behavior.

A common application of foot-in-the-door is when teens ask their parents for a small permission and then asking them for something larger. Having granted the smaller request increases the likelihood that parents will acquiesce with the later, larger request.

How would a store owner use the foot-in-the-door technique to sell you an expensive product? For example, say that you are buying the latest model smartphone, and the salesperson suggests you purchase the best data plan. You agree to this. The salesperson then suggests a bigger purchase — the three-year extended warranty. After agreeing to the smaller request, you are more likely to also agree to the larger request. You may have encountered this if you have bought a car. When salespeople realize that a buyer intends to purchase a certain model, they might try to get the customer to pay for many additional features like leather seating.