The Numerati are watching you. In this absorbing, sometimes scary book, award-winning BusinessWeek reporter Stephen Baker describes the mathematical elite who spend their days profiling us as shoppers, workers, voters, patients, potential terrorists; even as voyeurs and lovers. We don't know they're there, but every time we scan a website, use a cell phone, or buy something with a credit card, you're providing them with the data they need to understand and ultimately manipulate your behavior. With the help of Numerati savants, companies can sell you goods you never knew you wanted, and politicians can package themselves as candidates to match individual preferences. But, brace yourself, the trend is just beginning. "The mathematical modeling of humanity," he notes, "will transform every aspect of our lives." A stimulating ride for information addicts.