"Gladwell's best-seller looks at why major changes in our society so often happen suddenly and unexpectedly. He argues that ideas, behavior, messages, and products spread like outbreaks of infectious disease. Just as a single person with the flu can start an epidemic, a few fare-beaters and graffiti artists can fuel a subway crime wave; a satisfied customer can fill a restaurant's empty tables. The hopeful message is that one imaginative person applying a well-placed lever can move the world."