Bidding fee auction

Participants pay a fee to purchase bids. Each of the bids increases the price of the item by a small amount, such as one penny (0.01 USD, 1¢, or 0.01 GBP, 1p; hence the name of the auction), and extends the time of the auction by a few seconds. Bid prices vary by site and quantity purchased at a time, but generally cost 10–150 times the price of the bidding increment. The auctioneer receives the money paid for each bid, plus the final price of the item.

For example, if an item worth 1,000 currency units (dollars, euros, etc.) sells at a final price of 60, and a bid costing 1 raises the price of the item by 0.01, the auctioneer receives 6,000 for the 6,000 bids and 60 as the final price, a total of 6,060, a profit of 5,060. If the winning bidder used 150 bids in the process, they would have paid 150 for the bids plus 60 for the final price, a total of 210 and a saving of 790. All the other, losing, bidders collectively paid 5,850 and received nothing.

A TechCrunch article (July 26, 2010) on MadBid, one such site, called this model "a license to print money."[2] By contrast in an article on Madbid, The Guardian (28 January 2012) comments "legions of penny auction sites have folded, including Swoopo, Rapid Bargain and Bid Boogie."[3]

Due to the possibility of participants spending significant amounts of money and still losing an auction, or ultimately spending more than the retail value of the item they end up winning, some analysts have criticized the model or compared it to gambling, even when operating without fraud.[4][5][6][7][8] The Better Business Bureau warns consumers, "although not all penny auction sites are scams, some are being investigated as online gambling. BBB recommends you ... know exactly how the bidding works, set a limit for yourself, and be prepared to walk away before you go over that limit."[9] A penny auction may make the seller a far higher price than the item value.[1] Potential fraudulent practices which can disadvantage buyers even more include shill bidding, where a human or software (bot) bidder covertly acting for the seller places bids which make legitimate bidders continue bidding where otherwise the auction would end, and simply not sending out goods for which a price, albeit low, has been paid.

Some bidding fee auction sites have been shut down by state governments after investigations. Wavee US, LLC, settled with the Governor's Office of Consumer Protection in Georgia and agreed to close its website after the office received complaints about merchandise not being shipped in a timely fashion. Washington state shut down PennyBiddr after a lawsuit in which the state accused PennyBiddr of using shill bidding to drive up prices and extend auctions. In addition, several auction sites which claimed to be Better Business Bureau "Accredited" were not members of the BBB or had poor ratings with the BBB.[10]

• Dollar auction, a game theory experiment similar to penny auctions
• Unique bid auction, another auction style in which bidders pay for entry and ending prices are very low