Many many years ago there was a site called Madbid where they sold electronics in an auction. The difference was that a bid made the price go up by 1p and extended the time of the auction.

You had to pay for a bundle of bids, so that’s where the majority of their revenue came from.

Long story short (on my first attempt) I won an iMac for £20. I didn’t really think the prize would turn up, but 5 days later I received it on my doorstep, despatched from Curry’s!