I just don't understand why Amazon (and apparently Newegg) continue to do this. It's clear by now that sellers have abused it "launder" counterfeits into online retail fulfillment systems. Just charge an extra fee to the third-party seller to keep their inventory separate, have them stick a unique inventory barcode on it, and be done with it!

Because retail is a low margin business, but being a platform and collecting 15% off of top line revenue is much higher margin. Walmart’s market cap is $338B, Amazon’s is $1.3T. Even though Walmart’s share of retail dwarfs Amazon’s, clearly there is not much profit to be made.

You don’t have to deal with complaints, vetting products, or supply chain issues. Just side with the buyer in a dispute, and outsource all the other tasks to the customers who spend their time browsing through all the garbage on Amazon to save an extra few dollars.