Is there a science to persuasion? Dr. Robert Cialdini, a professor emeritus of psychology and marketing at Arizona State University, believes so. His research is revealing.
Here are six principles based on his research:
Reciprocity - People tend to return a favor, thus the pervasiveness of free samples in marketing. The good cop/bad cop strategy is also based on this principle.
Commitment and Consistency - If people commit, orally or in writing, to an idea or goal, they are more likely to honor that commitment because of establishing that idea or goal as being congruent with their self image. Even if the original incentive or motivation is removed after they have already agreed, they will continue to honor the agreement.
Social Proof - People will do things that they see other people are doing. For example, in one experiment, one or more confederates would look up into the sky; bystanders would then look up into the sky to see what they were seeing.
Authority - People will tend to obey authority figures, even if they are asked to perform objectionable acts.
Liking - People are easily persuaded by other people they like. Cialdini cites the marketing of Tupperware in what might now be called viral marketing. People were more likely to buy if they liked the person selling it to them.
Scarcity - Perceived scarcity will generate demand. For example, saying offers are available for a "limited time only" encourages sales.
These principles are explained in a video.