All of our auctions use the 15 Minute Rule. If a user places a bid within 15 minutes of the scheduled end date/time, the auction automatically switches into a special mode analogous to the "going, going, gone" of a live listing. In this mode, the listing is automatically extended until no bids have been placed within 15 minutes. When 15 minutes have passed with no bidding activity, the listing ends.
The purpose for the 15 Minute Rule is to prevent sniping and offer all users the opportunity to bid. The 15 Minute Rule allows all bidders an equal opportunity to place their best bid, and the seller can be assured he/she will receive maximum value for the item.