This always confused me. You have a bottle of glue sold by company X. Then you have 87 different people "buying" the glue in bulk, having it sent to Amazon, and selling it on Amazon as if it comes from their store:
Buying option 1: Company X glue from store A.
Buying option 2: Company X glue from store B.
Buying option 3: Company X glue from store C.
...etc.
But then Amazon says, "actually, these are all the exact same bottles of glue, so we'll thrown them all into the same bin, and no matter what "store" the people buy them from, we'll just grab them out and send them to the customer.
Now even without counterfeits, this is weird. What exactly is the point of store A, B, C, etc.? Company X sends the bottles to Amazon, they get put in one big pile, you buy them on Amazon, and Amazon takes them out of that one big pile and sends them to you.
The only thing purpose of the "stores" when you co-mingle inventory seems to be:
1. Plausible deniability for counterfeits. Hey, they told us they bought it from company X, we had no way of knowing they didn't.
2. Getting money from people trying to get rich quick in the marketplace. Some people will try all sorts of cuts to boost their Amazon sales in the hope that it will pay off later.