Whether you're in the market for some second hand scientific testing equipment or trying to find just the right retro doll houses for your collection, chances are you're most likely to find what you want at an online auction site like Ebay or Quibids. There are thousands of auction sites out there, so if you're looking to buy you should know how these auctions work and what you need to do in order to win.

There are several different ways of holding an online auction. One of the most popular (the method used on Ebay.com) is the English auction, in which bidders place public bids until all but one bidder remains. The Ebay model is slightly different in that it places time limits on bidding, leading to a practice known as sniping where discount aquarium supplies can be snapped up at the last moment by a new bidder who outbids the current high bidder without giving him or her time to counter. The system can also be instructed to enter more bids up to a maximum set by the bidder, turning the auction into a contest of who has the highest maximum.

Another type of auction you might find online is the Dutch style auction, wherein cable sheaves are offered for sale at a certain price and the price is lowered at regular intervals until a bidder accepts it. To ensure you win a Dutch auction, you must buy your item as soon as it hits your maximum price. Some sites that promise Dutch auctions, however, do not feature descending prices - simply price for purchase like retail.

A third type of auction you might see online is a sealed bid auction. In this type of auction, each bidder is permitted to make only one bid which is not shown to any other bidders. The items being auctioned off this way then go to the bidder who bid the highest. The best way to win this type of auction is to go in with your strongest offer, because there is no second round of bidding and you cannot base your price on anyone else's offer.

And finally, there are reverse auctions in some places on the internet, such as on Etsy's Alchemy page, the Elance freelance writing site, and the selection of government contractors. In this type of auction, it is the buyers who request an item or service, such as new cabinets or flooring. Sellers then approach the seller with how much they will charge for their product or service and the buyer chooses the cheapest auction that is satisfactory.

Businesses that don't auction as a reference.