Malcolm Gladwell, Priced to Sell , New Yorker , July 6, 2009. A review of Chris Anderson's Free: The Past and Future of a Radical Price . ... Anderson’s ... point is that when prices hit zero extraordinary things happen. Anderson describes an experiment conducted by the M.I.T. behavioral economist Dan Ariely, the author of “Predictably Irrational.” Ariely offered a group of subjects a choice between two kinds of chocolate—Hershey’s Kisses, for one cent, and Lindt truffles, for fifteen ce