Many dealers and OEMs are hesitant to dive into the certified pre-owned (CPO) market, but this segment has never been more important. For one thing, it’s growing fast. Currently, 3 million consumers are interested in a CPO vehicle, and that number could rise to 5.2 million by 2020. But what’s behind this increase? What makes CPO vehicles so compelling to consumers — and how can dealers and OEMs benefit from getting on board?