This article is for the review. Please help by adding reliable sources. Controversial material about living persons unsourced or poorly must immediately, especially if potentially libelous or harmful are removed. This article contains content is written like an ad. Please help to improve adding encyclopedic content written from neutral point of view by removing external links and inappropriate content and promotion. Reciprocity: people tend to do a favor, back, so that the wide distribution of free samples of marketing. Used in his lectures he often the example of Ethiopia thousands of dollars offered humanitarian aid to Mexico immediately after the earthquake of influence the psychology of persuasion liking 1985 despite Ethiopia suffering from a crippling famine and civil war in time. Ethiopia was an alternative to diplomatic assistance invaded the Mexico as Italy Ethiopia in 1935. Good COP, bad COP strategy is also based on this principle. Commitment and consistency-if people, orally or in writing to an idea or a target commit, they are more likely, this commitment through the establishment of this idea or something as in harmony with their self-image to honor. Although the original motivation or incentive is removed after they have already pledged, they will continue to honor the agreement. Cialdini Chinese brainwashing to write their self-image and auto gain notes to some American prisoners of war not enforced compliance. See cognitive dissonance. Social proof people are things do look, what other people do. For example, one or more confederates in the sky would look up in an experiment; Passers-by would look to see what they saw in the sky. At some point it stopped, how so many people raise were the traffic, have stopped. See compatibility and conformance tests by Asch. Authority people tend to authority figures, obey, even if questions lead behavior to reprehensible. Cialdini CITES incidents such as the Milgram experiments in the 1960s and the massacre at my Lai. Gusto people are easily convinced by other people who love them. Cialdini cites the marketing of Tupperware in what now-viral marketing could be described. People were more likely to buy, if it the person who wanted to sell them. Among many biases favoring more attractive people are discussed. See physical attractiveness stereotype. . .