It's the first time I saw "snipers" in this context. "Sniper" is the name we use in Poland for scripts set up to bid at eBay-like auctions. They are the reason I never buy anything from an auction (where I have to bid), and I stick only to buy-now, retail offers. It's because on any auction it's guaranteed that there is always some schmuck that will outbid you by 1¢ at the last microsecond with a sniper script. Proliferation of those scripts makes auctioning a waste of attention and emotional investment.

Its a flaw in the auction design. A simple rule as the closing time will be extended by x minutes after the last bid would solve this.

Our local auction site here in New Zealand, TradeMe, does that. Any bid in the last 2 minutes resets the clock to 2 minutes. Works pretty well for the seller, as prices tend to jump dramatically in these two minutes.

There is also at least one auction site with a similar business model that is practically a legal scam; bids cost money/points, and every bid increases the price by a fixed amount and extend the clock. Non-successful bids aren't paid back, of course.

There are actually some good arguments for a cost to bid system.

In theory it encourages people to bid their true preferences rather than waste time sniping.

Personally I find sniping quite enjoyable (as an idle-activity), but I also consider "recon" part of it (finding mislabelled or less widely known items that get the same job done usually results in huge effective discounts).