I can admit it freely now. All my life I've been a patsy. For as long as I can recall, I've been an easy mark for the pitches of peddlers, fund raisers, and operators of one sort or another. True, only some of these people have had dishonorable motives. The others - representatives of certain charitable agencies, for instance - have had the best of intentions. No matter. With personally disquieting frequency, I have found myself i possession of unwanted magazine subscriptions or tickets to the sanitation workers' ball. Probably this long-standing status as sucker accounts for my interest in the study of compliance: Just what are the factors that cause one person to say yes to another person? And which techniques most effectively use these factors to bring about such compliance? I wondered why it is that a request stated in a certain way will be rejected, when a request that asks for the same favor in a slightly different fashion will be successful.
-Robert B. Cialdini, from the Introduction to Influence: How and Why People Agree To Things