Book excerpt: Understanding Effective Advertising: How, When, and Why Advertising Works reviews and summarizes an extensive body of research on advertising effectiveness. In particular, it summarizes what we know today on when, how, and why advertising works. The primary focus of the book is on the instantaneous and carryover effects of advertising on consumer choice, sales, and market share. In addition, the book reviews research on the rich variety of ad appeals, and suggests which appeals work, and when, how, and why they work. The first comprehensive book on advertising effectiveness, Understanding Effective Advertising reviews over 50 years of research in the fields of advertising, marketing, consumer behavior, and psychology. It covers all aspects of advertising and its effect on sales, including sales elasticity, carryover effects, content effects, and effects of frequency. Author Gerard J. Tellis distills three decades of academic and professional experience into one volume that successfully dismisses many popular myths about advertising.