If a smaller request is granted, then the person who is agreeing feels like they are obligated to keep agreeing to larger requests to stay consistent with the original decision of agreeing. This technique is used in many ways and is a well-researched tactic for getting people to comply with requests. The saying is a reference to a door to door salesman who keeps the door from shutting with his foot, giving the customer no choice but to listen to the sales pitch.[4]