Looking at the articles from that seller, I don't even think they attach the articles for the reviews directly. It seems like they attach them to articles with

Looking at the articles from that seller, I don't even think they attach the articles for the reviews directly. It seems like they attach them to articles with many reviews, so that they can add their own fake reviews without being detected. If they made a new article, which immediately gets a lot of 5 star reviews, that'd be suspicious and Amazon would probably detect it. But if they attach it to an already established article, they can happily add their fake reviews and then detach them again, making it look legit. Just a theory though.