Jessica — not her real name — has spent well over $15,000 on Amazon this year, buying everything from Halloween decorations to a queen-size inflatable mattress. She’s purchased over 700 products, including three vacuum cleaners, six desk chairs, and no fewer than 26 pairs of earbuds. And even though most of the products are cheaply made, she’s given each a 5-star review. The twentysomething who lives on the East Coast isn’t a bad judge of quality — the companies that sell these products on Amazon reimburse her for the purchases.Although the loot may be free to her, Jessica’s habit does come with a cost — if you’ve considered buying an Instant Pot recently, her 5-star review, complete with photos and video, might have nudged you toward a knockoff instead of the real thing. It’s entirely fake, but Jessica told BuzzFeed News she doesn’t think she’s gaming the system; she’s trying to help brands grow their businesses in Amazon’s massive marketplace. “I’m just a pawn in their marketing scheme,” she said.Third-party sellers know what it takes to make it on Amazon: Get good reviews and a high search ranking. But attracting genuine customers is tough, so some sellers use a reliable…