John Wanamaker famously observed that "half the money I spend on advertising is wasted; the trouble is, I don't know which half." Indeed, though advertising is pervasive in our society, how it works (if and when it works) is not a question most of us can answer. In this Very Short Introduction, Winston Fletcher, a seasoned advertising veteran with extensive inside knowledge, offers an illuminating look at this billion-dollar business, dispelling some...