Imagine a bar that had a live bidding system for the price of drinks. The bar could purchase a whole bunch of discount alcohol and start the prices really low. Every time a customer makes a purchase, the price of that particular drink goes up for the next person.
The price could go down if that drink isn’t purchased for a certain period of time.
There wouldn’t really be any tangible benefit to this system, it’s more a gimmick for the bar to use to give people something to talk about.
Plus some days you might be lucky enough to grab a discounted beer.