Alibaba is the hottest e-commerce company of the past five years, a fusion of eBay and Amazon whose 386 million active users accounted for $394 billion in sales in fiscal 2015—six times the sales volume of its biggest Chinese competitor. The company created a huge marketplace and a sophisticated distribution network just in time to serve a generation of Chinese consumers attaining middle-class prosperity. “We are seeing Chinese consumers adopt new retail formats and online shopping faster than any of their global counterparts,” says Jasmine Xu, president of e-commerce for Procter & Gamble Greater China. Those trends fueled a rise so impressive that even the mighty Amazon became an Alibaba partner ... Today, however, Alibaba looks mortal. Its growth has slowed, hampered by China’s ebbing economy and by competition from a growing crop of rivals like JD.com. Its stock has fallen 26% from its post-IPO highs, from $115 to the mid $80s. To reignite its growth, chairman and founder Jack Ma and CEO Daniel Zhang plan to lean on U.S. companies—brands that hold enormous appeal in China. “This is an incredibly important strategy for the future of Alibaba,” Ma says. ... Alibaba is pitching itself as a shortcut to the world’s most populous market. Alibaba is helping foreign companies with marketing, data analytics, and shipping. And more recently it has sweetened the pot with a newer service, Tmall Global, that lets U.S. brands sidestep many of the taxes, regulatory hurdles, and logistics hassles that trip up foreign companies in China. ... Tmall, went live in 2008 with a business model sharply distinct from Taobao’s. Tmall is Zhang’s brainchild. He positioned it as a marketplace for higher-quality clothing, food, and electronics, with a focus on luxury brands. ... Tmall owes its growth to China’s rapidly expanding, brand-conscious middle class. Currently there are 109 million Chinese people with a net worth between $50,000 and $500,000, according to Credit Suisse, which estimates that those ranks could surpass 500 million by 2022. It’s a demographic that’s very comfortable with e-commerce: 40% of Chinese consumers buy groceries online, for example, compared with only 10% of Americans.