Influence: The Psychology of Persuasion by Robert Cialdini is a classic book that explores the principles of persuasion and how they can be applied to e-commerce. Cialdini explains the six universal principles of influence, including reciprocity, scarcity, and social proof, and provides practical examples of how they can be used to increase sales and conversions. This book is essential for anyone involved in e-commerce, as it provides valuable insights into consumer behavior and effective marketing techniques.