Since 1922, "Harvard Business Review" has been a leading source of breakthrough ideas in management practice. "The Harvard Business Review Classics" series now offers you the opportunity to make these seminal pieces a part of your permanent management library. Each highly readable volume contains a groundbreaking idea that continues to shape best practices and inspire countless managers around the world. This classic article shows how to make mass customization and efficient and personal marketing work by putting companies and their consumers in a 'learning relationship'. Over time, this ongoing relationship allows your company to meet customer's changing needs, develop learning relationships with them and retain their business forever.