Few companies have done more for global prosperity than Alibaba.com. Launched famously in China by Jack Ma, a former school teacher, in 1999, the company now connects 200,000 suppliers with millions of retail merchants. Suppliers grow, retailers diversify, and consumers have more choice for less money. Yet the B2B giant is not perfect. Language differences, intellectual property theft, and quality control can upend a supplier-buyer relationship. Rah Mahtani is Alibaba.com's head of commerc...