Sniper (auction bid)

A bid sniper is a person or software agent for timed, open auction web-sites (Yahoo!, eBay), that places a high bid during the last few seconds of bidding and prevents other users the opportunity to counter with a higher bid. [1]

This is often accomplished with the assistance of bidding software. On-line auction systems may attempt to discourage this by automatically extending the auction time when a last-minute bid is placed. This approach leaves all bidding open, and requires that bidders are watching during the final few minutes to counter-snipe any snipers. This approach can sometimes be 'beaten' by running sniper software on a faster internet connection (unless the system has bid flood protection), or by sniping against impatient and disgruntled manual bidders who 'give up' after several time extensions, but before reaching their maximum bid.

It can also lead to last-minute automated out-of-control bidding wars between snipers, which could extend the bidding time long beyond what the seller desired. Any site which implements a limit to the number of time extensions, simply causes a final extension snipe.

A second method to discourage snipers is to allow bidders to place a hidden or proxy bid, indicating to the system, but not the sniper, the absolute maximum they would be willing to extend their original bid, but without actually placing a bid. This can still be beaten by the sniper bidding in one dollar increments all the way up.

Properly implemented, this would be considered a form of closed auction system, where bidders can't see the current highest bid until they've actually out-bid it, and where winners pay a dollar more than the second highest hidden bidder. This second method requires the wise bidder to know in advance the value of an item and their limit for bidding on it, and to have trust in their auctioneer not to disclose this, even accidentally.

This method can only be beaten by a sniper who is willing to pay a little bit more than your hidden maximum. This second method also discourages 'bidding wars' or 'opportunistic' bidding on low-priced items, which may sometimes be beneficial in getting bidding started and escalating the price, and is part of the 'energy' of an open auction. However, improper implementation of the proxy bidding system introduces a new danger, maximum bid fishing: For some implementations of the proxy system, such as ebay, although the server does not disclose your maximum bid, it does not actually keep it a secret whether your maximum bid has or has not already been outbid.

This opens a loop-hole which allows an agent for the seller, using sniping software, to incrementally escalate their bid until they reach (and narrowly exceed) the current hidden maximum. They then hope to get one more bid increment out of the bidder, and thereby have successfully finessed the bidders maximum hidden bid out of the system.

However, in all cases, bid sniping is encouraging for the sniper, discouraging for the sniped, but not illegal as the sniper must actually be willing to pay more than the next highest bidder. In the end, getting sniped is really just a 'feeling' that you 'would have' extended your bid a dollar more, 'had you only known' that someone else would themselves pay a dollar more.

Having your bid fished-out is a feeling that 'you should have been able to' get the item for a lower price, if the seller had not been informed of how high you would bid.

Automatic bid sniping systems can be defeated by requiring people to enter numbers from a distorted picture of numbers, a CAPTCHA system that Eric M. Jackson stated was invented by Paypal.

External links

• Bidnapper Bidnapper
• eBay Snipe eBay Snipe
• AuctionSniper AuctionSniper