Airbnb has been giving brands like Hilton and Marriott a run for their money for a few years, but new data shows the company is taking a big chunk out of the hotel industries’ market share. According to a report by Second Measure , U.S. customers spent more money on Airbnb than Hilton hotels and is gaining on Marriott. Last year, the company held 19 percent of hotel market share and the number is expected to climb as Airbnb nears its IPO. Photo: Second Measure Convenience has long been on Airbnb’s side. The $31 billion company prides itself on having locations for customers in nearly every corner of the world. In November, the company announced an update that lets groups split payments for trips. Subtle improvements have had huge impacts on Airbnb’s sales. According to the report, the company’s sales have tripled in the past three years. Airbnb’s retention numbers also shine a light on some of its success. In 2017, 40 percent of Airbnb customers returned within a year. Marriott and...