How penny auction site works?

Penny auction sites are also called Reverse Auction site because they are not like a general auction you have seen at eBay or other eCommerce site.

It is a pay per bid auction wherein the bidders have to pay for each bid that they place on the auctions. Bids are in the form of ‘Bid packages’. Usually, the package contains 15,20,100,etc bids.  In return, the winner gets the item with an amazing bargain.  The winner will be the last bidder when the clock reaches zero.  When a bid is placed, the auction price will go up by 1 cent and the timer running under the auction will increase by few seconds.(addition of seconds are different for different penny auction websites). Adding few seconds will give a chance to other bidders to place a bid. This way competition and interest increases.