RFID is a possible solution. Tags are now about five cents, and likely to drop further in price with volume. Newer tag designs can be sewn in the seams of garments and shoes.
Commingling is optional to Amazon vendors, all they have to do is track each item with a plain individual sticker / QR tag. They opt not to do it and track using the generic product barcode since it's cheaper and simpler.
So if they can't be bothered to attach a zero cents sticker on the item, a 5cents rfid tag is out of the question.
The commingling thing is crazy overblown. One of those internet memes that just grows legs and the legend can never live up to its original source.
If it’s both fulfilled and sold by Amazon, I have yet to have anyone actually provide an actual first person story that their item came from commingled or forged stock.
Yes, I’m sure it has happened. It’s not a widespread thing. Amazon does not sell Tide detergent sourced from some random third party that sent in stock matching the SKU being sold because it happens to be in a closer warehouse.
Random listings on Amazon? Sure I’ve received fake stuff. That’s the risk of using a third party storefront.
I have also not heard or seen of a well sourced story recently where someone’s esoteric custom product SKU was being sent in by third parties as the same ASIN and comingled with the legit companies listing.
The shady listings seem to be where this all comes from to begin with. Amazon could cull those nearly overnight but chooses not to. This is where the main problem lies. The times you click the legit listing for the FBA/SBA Amazon item, and then there are 12 “options” like multi-packs that are random third parties trying to take advantage of the unaware type of dark pattern.
