> I thought I read in HN many times that commingled items can be supplied from any vendors supply and not the one a buyer chose. Correct. > What does it mean

> I thought I read in HN many times that commingled items can be supplied from any vendors supply and not the one a buyer chose. Correct. > What does it mean that they track it but don't ensure that proper items are delivered It means Amazon can send an item originally supplied by any seller, but Amazon will know who the original seller was. > and what's the advantage of amazon to commingle. Reduced fulfillment cost by e.g. having the stock closer to the buyer and reducing the need to ship orders from multiple warehouses (due to orders containing various different products and/or different sellers), as they have more inventory of that product to distribute throughout their warehouses. > Another thing is if Amazon actually fulfill one buyer's sell through another's supply how is this not a fraud by amazon and how they are not sued out of business even without any fake item issue? Both sellers have agreed to commingling. When you buy from seller A but seller B has stock closer, sellers A and B will perform a trade (automatically) where A gets one item of B's stock and B gets one item of A's stock. And then the now A's item will be shipped to customer. So at the time of shipping it is A's item, as the customer ordered.