EDIT: just saw that poloponies got here way first. 🙂
These are penny auction websites, kind of a neat idea especially for the proprietors of such websites, as they probably make 10 times the full retail of an iPad after they sell it to you for $23.
How? I'm no expert, but it goes something like this...
You pay up front for bidding "credits," and each bid on the item is only a penny, but there are hundreds of bidders, each paying a set amount for each bid they place. The or ice on the item creeps up and up penny by penny, and there is a countdown timer until bidding closes, and the pat timer gets 10 seconds added to it with each bid placed.
So basically in the end, one lucky bidder is on top when the timer expires and you may have spent $50 trying to win it, meanwhile, there has been 2300 bids placed at something like 50 cents a bid, or close to it. At that rate per bid (maybe more, even) the website just made at least $1150 on the auction, bought the iPad for $499+tax, and the winner pays $23 plus whatever it cost him to make the bid(s).
No do this 1,000 times a day on everything from cars to household items like cleaning supplies. Pretty good racket, eh? 🙂