On Amazon’s marketplace, where independent merchants collectively sell billions of dollars in goods , Chinese sellers have become a powerful force, in part due to Amazon’s heavy recruitment of them in recent years. But a few months ago, the e-commerce giant began suspending the accounts of some of its large and successful Chinese merchants. The reason, it emerged, was abuse of Amazon’s review system. Since then, Amazon has shuttered at least 50,000 stores operated by Chinese merchants, according to a Shenzhen-based trade group , for behaviors such as soliciting fake reviews and offering gift cards to reviewers, the latter being…