What our results suggest is that because what people like depends on what they think other people like, what the market "wants" at any point in time can depend very sensitively on its own history: there is no sense in which it simply "reveals" what people wanted all along. In such a world, in fact, the question "Why did X succeed?" may not have any better answer than the one given by the publisher of Lynne Truss's surprise best seller, "Eats, Shoots & Leaves," who, when asked to explain its success, replied that "it sold well because lots of people bought it."