The worldwide bestseller on the theory and practice of persuasion. Marketing expert and social psychologist Robert B. Cialdini explains why people say yes and how this knowledge can be applied. Cialdini outlines the six fundamental principles of persuasion and demonstrates how to use them to protect oneself from influence or to become more persuasive. Based on over thirty years of research and illustrated with numerous examples from all areas of life, this book offers invaluable assistance to those looking to advance successfully in their careers or personal lives. The bestseller has been published in millions of copies and is highly praised for its readability, practical insights, and scientific accuracy. The book has garnered an enthusiastic readership among business and marketing professionals.