A combination of wanting 1) the best price 2) fastest shipping times 3) the world's largest catalog and 4) profit. You're buying some item. You're in New York

A combination of wanting 1) the best price 2) fastest shipping times 3) the world's largest catalog and 4) profit. You're buying some item. You're in New York City. Other websites sell it for $20. You go on Amazon.com and see that it's $14.99, here's where #1 comes in. Why is it so low?? In our scenario, let's assume "Fugazi FBA seller" just shipped in a bunch of counterfeit merchandise into Amazon's warehouse in Tennessee that cost them $5.00, $14.99 is a major win for the seller. Now, Amazon matches the price at $14.99 and you buy it "ships and sold by Amazon". This is where #2 comes in. You're a Prime member. You expect to get it in 2 days. You're all the way out in NYC. The closest warehouse that has Amazon's legit inventory is in California. Amazon says, "Hey we need to get this customer his/her item in 2 days. It's way FASTER and CHEAPER, if we just pick one unit from Fugazi FBA seller's stock that's in Tennessee and ship that out." - #2 and #4. Once this product is end-of-life or Amazon can't source it, #3 comes into play and Amazon stops selling it "ships and sold by Amazon" and sellers (legit and illegitimate) are left to fight it out.