Many of us who surf the internet enter into a kind of personal contract that our tastes are tracked because we see more custom ads of things we want to buy, people we want to date, and places we want to go. But how much of our lives are being put into patterns? And who uses that information? STEPHEN BAKER looks at the trends and logic behind them that mathemeticians are using to predict our future behavior in his new book, ???The Numerati.???