Amazon.com Inc was marketing a collection of President Xi Jinping’s speeches and writings on its Chinese website about two years ago, when Beijing delivered an edict, according to two people familiar with the incident. The American e-commerce giant must stop allowing any customer ratings and reviews in China. A negative review of Xi’s book prompted the demand, one of the people said. “I think the issue was anything under five stars,” the highest rating in Amazon’s five-point system, said the other person. Ratings and reviews are a crucial part of Amazon’s e-commerce business, a major way of engaging shoppers. But...