Influence: The Psychology of Persuasion
by Robert B. Cialdini
Edition: Revised - 1993
Some people just won't take no for an answer. In Influence, Dr. Robert Cialdini explains the six psychological principles that drive our powerful impulse to comply to the pressures of others and shows how we can defend ourselves against manipulation (or put the principles to work in our own interest).
Influence guarantees two things: Readers will never say yes again when they really mean no, and they'll be more persuasive than ever before.