Blackhat techniques from some Amazon sellers
Here are a couple of the latest black hat techniques being used in the Amazon FBA marketplace.
Both involve your listings that ran out of stock.
Sellers that have software that tracks out of stock listings, then they create a variation of the product in that listing (even if the product is not even slightly related)
This way they can create variations of the existing listing and keep all existing reviews.
Quin Amorim, Host of Amazon FBA Selling Online Podcast