This book explores what marketing is and how an enterprise can differentiate itself from others in attracting and retaining customers. The book is organized according to the design of the first-year marketing course in the two-year MBA program at the Harvard Business School. Each chapter of the book is written by HBS faculty and used by MBA students in preparation for classroom participation. The book consists of three parts: the analysis of marketing opportunities, the formulation of marketing strategy, and the execution of that strategy.