I often see reviews for a model that's similar but still different. Not being a seller, I'm guessing the exploit is around labelling a different model / product

I often see reviews for a model that's similar but still different. Not being a seller, I'm guessing the exploit is around labelling a different model / product as a colour variation of the product they're trying to leech off, and voila: now the crappy product has the same rating / reviews as the original, better product.