In 2009, Netflix offered $1 million to anyone who could improve the quality of its recommendation engine by 10%. It took two years, but a team finally won. Netflix paid the bounty--then ignored the code. As it turned out, the enhanced algorithms "did not seem to justify the engineering effort needed to bring them into a production environment." Not only did the winning prediction engine fail to scale economically, it also addressed an outdated problem: The shift from mail to streaming during that same two-year window gave Netflix all the data it needed to develop newer, better algorithms. Nor, in the decade since, has it become one.