Uber’s second line of business, Uber Eats hot-food delivery service, is indeed hot. According to a research firm that aggregates credit card purchase data, Uber Eats passed publicly traded Grubhub in more than a dozen big cities such as Houston, Atlanta, and Seattle. It also has staying power: On average, 41% of Uber Eats customers are using it regularly six months after their first order. For Grubhub, the figure was 17%. Perhaps it’s because Uber controls the drivers who deliver the meals whereas Grubhub relies on drivers hired by the restaurants in its marketplace—and thus it can’t ensure a speedy experience. Overall Uber Eats still has 20% market share in the U.S. compared to Grubhub’s 50%, according to the study by Second Measure. And it still operates in the red. But it seems to be the kind of sticky service Uber may be able to profit from in the future.