Not sure where to find a reference, but ISTR it's been shown that the bidding sequence in penny auctions is functionally indistinguishable from a random process

Not sure where to find a reference, but ISTR it's been shown that the bidding sequence in penny auctions is functionally indistinguishable from a random process (provided that bidders aren't colluding to throw the auction to a predetermined winner), in much the same way that die rolls or coin flips are functionally random even though they're determined by a person applying mechanical forces. And unlike conventional auctions, all bidders end up paying. They don't pay the final "auction price", but they do pay a fee for placed bids. So the practical upshot is that this functions like a raffle or lottery, with the "auction" elements basically being window dressing.