[coaxial]

So my understanding is this: as a seller, buy subpar version of whatever item. Send it to Amazon to be comingled with every other item sent to Amazon for that SKU. Sit and wait, Amazon will use some of your stock to fulfill orders from this listing (so other sellers' sales will result in buyers receiving some of your stock). You'll also make sales yourself, and Amazon will send whatever stock from that pool of item (so not necessarily the exact ones you sent in, and most likely the genuine/better quality ones other sellers sent it). You make the sale, keep the money. Meanwhile, the buyer who got your item when buying from another seller will complain and return their item. The seller (not you!) will have to issue the refund and eat the cost. Voilà, you've exploited amazon's comingling to your profit and actually made money off of it.