Have you ever wondered how certain foods become trendy seemingly overnight? Take the cupcake, for instance. What once was a standard childhood treat, in recent years, has become a chic confection. Journalist David Sax tracked the origins of the cupcake fad and other trends for his book "The Tastemakers: Why We're Crazy For Cupcakes But Fed Up With Fondue." He spoke with Sara Nics about why fads strike a chord with people.