Let me illustrate. Here I am, Clayton Christensen. I’m sixty-four years old. I’m six feet eight inches tall. My shoe size is sixteen. My wife and I have sent all our children off to college. I live in a suburb of Boston and drive a Honda minivan to work. I have a lot of other characteristics and attributes. But these characteristics have not yet caused me to go out and buy the New York Times today. There might be a correlation between some of these characteristics and the propensity of customers to purchase the Times. But those attributes don’t cause me to buy that paper—or any other product.
