Auction sniping is the process of watching a timed online auction (such as on Ebay), and placing a winning bid at the last possible moment (often seconds before the end of the auction), giving the other bidders no time to outbid the sniper. Some bidders do this manually, and others use software designed for the purpose. A bid sniper is a person or software agent who performs auction sniping.
There are also online sniping services, where the software agent is run from a website rather than the sniper’s own computer. This decreases the failure rate of the snipe, because the website is expected to have more reliable servers that might be quicker to react.
While auction sniping is frowned upon by some people, it does not break any of the rules established by eBay. However, eBay Germany did ban automated sniping services in 2002.
A few other auction sites (such as iGavel, the New Zealand auction site TradeMe, and the real estate auction site Bid on the City) automatically extend the bid deadline by a few minutes if a bid is placed in the last moments of the auction, to give other buyers time to react. There are few possible ways of sniping prevention: one being to extend the time as described above and another is to end the auction at a random time (i.e. ending the auction at an undisclosed time in the final hour).