Two of my business heroes are Samuel Brannan and Sylvester McMonkey McBean. Brannan was a pioneer who made his fortune during the Gold Rush in California, not by searching for gold, but by selling shovels and other tools to prospectors. McBean, otherwise known as the "fix-it-up-chappie", capitalized on the pride of Sneetches as they ran around getting and removing stars on their bellies.
In essence, these entrepreneurs not only found and met a customer need, but they also leveraged social disruption to their advantage. It was brilliant of them to tap into something much deeper than a mere want for a product or service. Instead, these two examples show the importance of understanding the motives why customers make the decisions that they do, and then finding a way to help them achieve their desire.
Another interesting point about the Dr. Seuss example is that McBean didn't care a bit about whether the Sneetches wanted to get a star or have a star removed. He simply fed off of their fickleness and facilitated their changing tastes. Greedy? Maybe. But also genius.