As of May 2015, the biggest online auction sites include eBay.com, uBid.com, QuiBids.com and Beezid.com. Users also have access to government surplus auctions through GovDeals.com.
eBay has been in the online auction business since 1995. The site allows sellers to conduct standard auctions with an optional "Buy It Now" price that ends the auction early. Users can also sell Items for a fixed price by only using the "Buy It Now" option.
uBid operates in a format similar to eBay, with both fixed-price and regular auctions. Unlike eBay, the company certifies all of its third-party sellers and also sells some items directly.
QuiBids advertises itself as a penny auction site, but currently a Quibids "penny" is equal to 60 cents. This is the minimum bid increase for auctions on the site. Losers of the auction also have the option of paying the full retail price for the item.
Beezid also advertises itself as a penny auction site. Bid increases are actually a penny, but users must purchase bids in lots of 30 or more. Making a bid on an item expends one of these purchased bids and increases the item price by one penny. The site does not return bids to those who lost the auction.