This high cost is also what led to the growth in popularity of low-cost carriers, a concept initially pioneered by Southwest Airlines, and later mimicked by Ryanair.
As with a standard auction, the bidders, having made a judgment on how much a particular voyage is worth to them, place their bid over a set period of time.
At the end of this period of time, the highest bidder wins the product at whatever price is finally reached.
Some sites also operate a system of mystery auctions, whereby the bidder is unaware of the product they are bidding on.
Research from Brown University [3] suggests that such penny or pay per bid auctions have been able to survive thanks to customer retention initiatives such as the Buy-Now functionality which offsets the outright purchase price option of the good by the cost of the bids that the user has incurred, and also by limiting the number of times a particular user can win, leading to a greater pool of winners.