Omer Ismail, CEO of the Walmart-backed fintech OnePay, thinks he’s found the way around it: Piggyback on the country’s biggest retailer. Most of OnePay’s 7 million customers have been drawn from Walmart’s base of 1.5 million employees and 150 million or so shoppers — acquired for free. “The issue has been just how hard it is to acquire customers,” Ismail said on the latest episode of Semafor’s Compound Interest. Walmart has spent more than two decades trying to crack financial services, with mixed success. Walmart is OnePay’s majority shareholder, but it is being built separately — for starters, in New York, far from the retailer’s home base in Arkansas.