For novice eBay bidders, it is a common disappointment.
They submit the highest offer in the last few minutes of bidding, confident in the likelihood of winning.
Then suddenly, with seconds to go, someone else swoops in with an even higher offer. Before the novice has time to retaliate, the auction closes.
In eBay jargon, the second-to-last bidder has been hit by a sniper.
"It's a phenomenon that can only exist in the online auction world," said David Steiner, president of AuctionBytes and a buyer and seller of collectibles on eBay. Steiner said it's not uncommon to see moderately priced items surge several hundred dollars in the final seconds of bidding.
Although sniping has existed in one form or another almost since the inception of eBay, Steiner said the practice has grown increasingly prevalent of late, fueled by experienced auction buyers competing for bargains.
The popularity of sniping has in turn created a cottage industry of sniper services offering tools for auction addicts. Offerings range from downloadable software to hosted services that charge a fee for placing a bid.
"Now everyone snipes," said Tom Campbell, president of eSnipe, a hosted service that charges users 1 percent of each winning bid, up to $10. "If you put something up for sale, it just sits there until a few minutes before the end of the auction."
Campbell should know. He purchased eSnipe on eBay in 1999 by sniping.
Other services simply offer software that automatically places last-minute bids, up to a predetermined maximum. One advantage of using sniping software is that it's generally cheaper for active bidders than using hosted services, said Dan Hite, developer of a sniping program called Auction Sentry that sells for $10.
Companies that sell hosted sniper services say a disadvantage of do-it-yourself sniping software is that users have to monitor the auction themselves. With a hosted service, bidders can simply submit their maximum acceptable bid, and let the company handle the rest.
Of course, for true auction addicts, being there at the last minute is part of the thrill.
"It really is an actual rush," said Marcia Collier, author of EBay for Dummies and a habitual sniper.
"A lot of people who don't snipe feel it's unfair," she said, recalling a nasty e-mail from a rival bidder she sniped out of a book. "But it happens to be my absolute favorite way to win at auctions."
Collier says she often prefers to enter her last-second bids manually, without the help of any professional sniping applications. It may not be the most efficient method, but it makes the auction exciting.
The fact that many of its most dedicated fans are snipers isn't lost on eBay. Nor is the fact that many other buyers and sellers wish they would go away -- a viewpoint expressed frequently on eBay message boards.
The auction site has taken a decidedly neutral stance on the matter.
"We know it's there," said eBay spokesman Kevin Pursglove. "It's a tool that many of our users like, and it's a tool that frustrates many of our users. But it's up to our users whether or not they want to use a sniping tool."