The human tendency toward needing to appear consistent is one factor that contributes to the success of the compliance techniques.

the human tendency toward needing to appear consistent is one factor that contributes to the success of the foot-in-the-door and low-ball compliance techniques. The foot in the door technique happens when you want someone to agree to a large request so first you get them to agree to modest requests before the big request. Low ball technique is when an item is offered at a much lower price than the market, then it is raised to gain profit.