Obscure Chinese makers of everything from wireless headphones to kitchen mops that wanted to crack the U.S. market for several years have turned to the world's biggest e-commerce company for help. They use an Amazon.com Inc. program called Fulfillment by Amazon (FBA) that allows third-party merchants to store their goods in its warehouses and let the U.S. company handle delivery, returns, and exchanges. To get attention on Amazon's sprawling marketplace, many Chinese sellers offer freebies or even cash to consumers willing to write favorable product reviews. Amazon once allowed such incentives in exchange for reviews to help introduce products to customers. But it began discouraging the practice in 2016, realizing freebies compromised the integrity of customer reviews. Many merchants ignored the new rules by recruiting shoppers on Facebook and reimbursing them via PayPal to elude Amazon's detection, and the problem persisted. Although review incentives-except those solicited through Amazon's own Vine review program-violate rules, for years the company was eager to have more Chinese merchants offering an abundant supply of low-priced goods via FBA and didn't seem to aggressively enforce its policies. But now Amazon is cracking down on pay-for-praise schemes, which can include other forms of consideration for reviews including free extended warranties, discounts or refunds, or gift cards, as the company looks to restore a sense of order to its previously free-wheeling marketplace. Starting in the second quarter, Chinese industry observers say, the company abruptly changed course and began suspending retailers and freezing their inventory at its U.S. warehouses. More than 50,000 Chinese retail accounts have lost their place on the platform, resulting in lost sales of 100 billion yuan ($15.4 billion), according to the Shenzhen Cross-Border E-Commerce Association. "Suppliers cannot be repaid, bank loans cannot be applied for, employees are facing unemployment, and the profits of the past few years have been emptied overnight," says Wang Xin, the association's president. The industry "has been almost completely broken." Amazon's policy to crack down on the misconduct of fake reviews applies to all sellers, but based on data tracked by New York-based data consultant Marketplace Pulse, all the recently suspended accounts were based in China. The e-commerce giant rejects accusations that it's unfairly punishing Chinese companies. "We ... adhere to the principle of fairness and deal with sellers' violations without discrimination, regardless of the size of the seller's business or which country or region it is from," the company said in a May statement. And on Aug. 14, an Amazon spokesman in the U.S. reiterated its position. "We don't tolerate fake or paid reviews from any seller," he said in an email. "We have always prioritized protecting our store from fraud and abuse and taking the appropriate actions to hold bad actors accountable." An Amazon.cn delivery person hands a package to a customer. One of the biggest Chinese casualties is Shenzhen Qianhai Patozon Network & Technology Co., maker of a formerly hot-selling headset brand Mpow, which has been dark on Amazon since April. The company issued a public letter in May saying it was "closely communicating with Amazon and actively applying for reinstatement" and described the process as "positive." But this month the company halted its research and development team's operations for the rest of the year and is encouraging employees to seek jobs elsewhere, according to a person familiar with the matter who doesn't have authorization to speak with the media. Robots move shelves at the Amazon fulfillment center in Baltimore. Photographer: Melissa Lyttle/Bloomberg For Chinese companies suspended by Amazon or worried that they might be next, finding alternatives isn't easy. Walmart last year launched an FBA rival, Walmart Fulfillment Services, for the retailer's online marketplace, but so far it isn't a great option, according to Jason Lee, co-chief executive officer of FBAFlipper, a Shenzhen-based advisory firm. "Amazon is just addicting because it has the traffic already," says Lee, who also points to the support network that companies can use when selling on Amazon. "There's an ecosystem-people with courses [on] how to sell on Amazon, logistics providers, payment companies." Walmart's service doesn't have them, he says. faux saint laurent bag