Proxy bidding is part of the eBay bidding system that enables a bidder to set an absolute maximum that he is willing to bid. The system then places bids automatically on the person's behalf until it reaches his maximum bid.
The eBay proxy system automatically increases bids for every bidder in an auction, and continues until all bidders except the winner are outbid. The system uses technology to monitor the bidding process so that bidders do not have to monitor it in real time.
Proxy bidding is used in all auctions except a Dutch Auction, which sets the price after all of the bids are placed.