I overhead a friend talking about eBay chicken. I enquired what on earth it was and found out that it is when you have reached your own threshold but bid above it not to win, but to drive up the price on the person who outbid you. If you make the wrong judgement call then you could end up with the item for much more than you anticipated paying.
A second related phenomena eBay roulette occurs when you and some friends get back from the pub in a tired and emotional state and take it in turns to bid up an auction that is due to close very soon. The item has to be something that you don’t want (ie: a signed autograph of Gary Glitter or a Laura Ashley blouse) until one of you ends up the with the literal booby prize and has to drink a penalty drink (whatever is around the house) and then another soon-to-close auction is selected and bidding begins again.