This is referred to as a "Soft Close" and is common within the online auction industry. The bidding is extended by 10 minutes from the last bid registered and will continue to do so as long as there is bidding taking place. The item will close once there has been a 10 minute dormant period of no bidding. This is done to prevent bidders from waiting to the very last second to place a bid and "stealing" it from the current high bidder who may have wished to continue the auction process. This method also more closely resembles a traditional live auction in that the auction continues until bidding has ceased.
Why does the auction close time keep extending ten minutes?
