China's largest coffee chain is taking on the U.S.Luckin Coffee, which unseated Starbucks as the top chain in China, is now making a big play in the Seattle-based stalwart's home country. As of mid-September, Luckin has opened 5 locations in New York City.Luckin stores operate without cashiers, and customers must place orders on its mobile app. Although the sticker price of its drinks are not that far off from those at Starbucks, Luckin's operating model relies heavily on discounting by showering users with ...