A lot of people wouldn't like Coca-cola scammers. They'd want the real Coca-cola. And these people would be willing to pay a small premium for it. So stores would have an incentive to sell the real thing. A lot of stores would probably refuse the sell the scam Coca-cola.

But a lot of other people wouldn't care, and they'd happily drink the scam Coca-cola which tastes just like the real thing, but is made by somebody else, and is cheaper.