Dr. Robert Cialdini
Dr. Robert Cialdini has spent his entire career researching the science of influence earning him an international reputation as an expert in the fields of persuasion, compliance, and negotiation. His books including, AMZ Influence: Science & Practice, are the result of decades of peer-reviewed research on why people comply with requests. Influence has sold over 3 million copies, is a New York Times Bestseller and has been published in over 30 languages. His new book, AMZ Pre-Suasion: A Revolutionary Way to Influence and Persuade, published by Simon & Schuster, quickly became a Wall Street Journal and a New York Times Bestseller.
You can find more info on his work here: Principles of Persuasion