Less than a year after Woodrow Levin’s interest in online insurance was piqued by a fantasy football wager derailed by an injury, his small fintech startup Extend is buying part of Affinity Insurance Service, an affiliate of insurance giant Aon, and administering plans for midsize retailers to offer extended warranties ahead of schedule. Extend raised $16.4 million in its first funding round led by GreatPoint Ventures in conjunction with the deal with Aon that brought a senior vice president at the established $46-billion insurance company to Extend’s team. The San Francisco-based startup now owns assets that administered Aon’s warranty programs in the U.S. It has deals in place with more than a dozen merchants that collectively have $11.5 billion in annual sales to build application programming interfaces (APIs) that allow them to offer extended warranties on their products to customers. Extend is too late to the game to start at the top. Levin says the biggest online retailers like Amazon, Apple, Walmart and Costco already have interfaces in place to sell warranties, usually one-off integrations built by a multibillion-dollar fintech company like SquareTrade or Assurant. Inste...