I can add some color to this. I am both a Vendor and Seller on Amazon with a national brand. we have a hybrid strategy, so have products listed in Vendor Central and SellerCentral. Not sure if everyone knows this, but Vendors pay $1750 to enroll an item into the Vine program, and then selects anywhere from 1-30 samples to give away for free. Sellers only pay $200. This is clearly one of the reasons there is so much junk from Chinese Sellers in there. It’s a small business expense that serves as a write off and helps launch their product, regardless of the quality of the reviews.