Robert Cialdini, a persuasion researcher at Arizona State University in Tempe, enrolled in dozens of sales training programs, learning the tricks of selling. He found the most effective tactics were rooted in six principles. Most are not new but are being used with greater sophistication.
* Reciprocity: People have been trained to believe that a favor must be repaid in kind, even if the original favor was not requested.
* Commitment and consistency: People tend to feel they should be consistent -- even when it no longer makes sense.
* Social validation: People often decide what is correct based on what other people think.
* Liking: People prefer to comply with requests from people they know and like.
* Authority: People defer to authority.
* Scarcity: Products and opportunities seem more valuable when the supply is limited.