Cables are notorious for this - almost every knock off type cable I've purchased from Amazon has come with an envelope asking for a review and they will provide a free gift for me. Most of those purchases go back to Amazon and I try to review them accordingly, but it's hard to judge when you've got more than 200 reviews and averaging 4.5 stars on a very specific cable you're looking for (length, color, specs, etc). In these cases Amazon eats significant shipping costs for the send and return labels - you'd think they'd want to get this under control better. But if anything I'd say returning the item is the best way to get Amazon to crack down on this since these fake reviews then cost them time and money.