It's intuitive to me that sniping can be advantageous but a group of physicists have shown it through mathematic modeling. As pointed out earlier, if I bid the maximum I'm willing to pay early on, sniping has no effect on me. If I lose, the sniper was willing to pay more. But people aren't always rational on eBay and I've seen those bidding frenzies so as a buyer, I bid in the last few seconds (manually) and as a seller, I like to see early bidding. Here's the USA Today article about the research. To test whether sniping is a smart way to do things or just truncates normal bidding, the South Korean team at Seoul National University produced a "master equation" for how bidding proceeds (it's nk(t+1) — nk(t) = w(k-1)(t)*n(k-1)(t) — wk(t)*nk(t) + sigma(k,1)*u(t), if you really want to know), and then tested it against a massive number of auction records, some 264,073 items sold in one day on eBay and another 287,018 items sold in one year by eBay's Korean partner. Plugging all those data into the model and testing the outcome in terms of how the auctions turned out, the team found that the probability of submitting a winning bid on an item indeed drops with each bid. "Our analysis explicitly shows that the winning strategy is to bid at the last moment as the first attempt rather than incremental bidding from the start." The study appears in the current Physical Review E journal. The finding is no surprise to Harvard economist Alvin Roth, who has studied sniping from an economics viewpoint since 2002 with colleague Axel Ockenfels of Germany's University of Cologne. They came to similar conclusions. "I think you might do the most good if you advise bidders to form an opinion of how much they are willing to pay for an item, so that they don't get caught up in a bidding war and pay more than they will be happy with," says Roth, by e-mail. "But, that being said, if they know what proxy bid they want to submit, it won't hurt them to submit it very near the end (but neither will it help them much, or often ...) So, sniping is a good strategy, for those with the time to do it," he adds.