Hugh Pickens writes "For decades, Target has collected vast amounts of data on every person who regularly walks into one of its stores. Now the NY Times Magazine reports on how companies like Target identify those unique moments in consumers' lives when their shopping habits become particularly flexible and the right advertisement or coupon can cause them to begin spending in new ways. Among life events, none are more important than the arrival of a baby, and new parents are a retailer's holy grail. In 2002, marketers at Target asked statisticians to answer an odd question: 'If we wanted to figure out if a customer is pregnant, even if she didn't want us to know, can you do that?' Specifically, the marketers said they wanted to send specially designed ads to women in their second trimester, which is when most expectant mothers begin buying all sorts of new things, like prenatal vitamins and maternity clothing. 'We knew that if we could identify them in their second trimester, there's a good chance we could capture them for years,' says statistician Andrew Pole. 'As soon as we get them buying diapers from us, they're going to start buying everything else too.' As Pole's computers crawled through the data, he was able to identify about 25 products that, when analyzed together, allowed him to assign each shopper a 'pregnancy prediction' score and he soon had a list of tens of thousands of women who were most likely pregnant. About a year after Pole created his pregnancy-prediction model, a man walked into a Target outside Minneapolis and demanded to see the manager. He was clutching coupons that had been sent to his daughter, and he was angry. 'My daughter got this in the mail!' he said. 'She's still in high school, and you're sending her coupons for baby clothes and cribs? Are you trying to encourage her to get pregnant?' The manager apologized and then called a few days later to apologize again but the father was somewhat abashed. 'It turns out there's been some activities in my house I haven't been completely aware of. She's due in August. I owe you an apology.'"