Six weapons of influence ( 3 and 4 of 6)

Men of good judgement seldom rely fully on their own

Principle#3: Commitment and Consistency

People do not like to back out of deals. We are more likely to do something after we have agreed to it verbally or in writing. People strive for consistency in their commitments. They also prefer to follow pre-existing attitudes, values and actions. We decide what is correct by noticing what other people think is correct. This principle applies especially to the way we determine what constitutes correct behavior. If everyone else is behaving in a certain way, most assume that that is the right thing to do. This principle of influence kicks in even more strongly when the situation is uncertain or people are not sure what to do. For instance, you would probably be more likely to support a colleague's project proposal if you had shown interest when he first talked to you about his ideas. 

Gorden Sinclair, a Chicago restaurant owner, was beset by the problem of no-shows—people who made table reservations but failed to appear and failed to call to cancel. He reduced the problem by first getting a small commitment. He instructed his receptionists to stop saying, ‘Please call if you change your plans’ and to start saying, Will you call us if you change your plans?’

The no-show rate dropped from 30% to 10% immediately.

Principle#4:Liking

People prefer to say ‘yes’ to those they know and like. People are also more likely to favor those who are physically attractive, similar to themselves, or who give them compliments. People love to say ‘yes’ to requests from people they know and like. And people tend to like others who appear to have similar opinions, personality traits, background, or lifestyle. More people will say ‘yes’ to you if they like you, and the more similar to them you appear to be, the more likely they are to like you. 

Companies that use sales agents from within the community employ this principle with huge success. People are more likely to buy from people like themselves, from friends, and from people they know and respect.