You may not be familiar with private auctions on eBay as they are only used by the minority of sellers. Private auctions, are exactly the same as regular auctions except you can not see who you are bidding against. All users who participate in these auctions are completely unknown to each other.

The first time I bidded in a private auction I was a little skeptical, after all it would be very easy for the seller to take advantage of the privacy factor & bump up the auction price though the practice of shill bidding. I'm guessing I'm not alone here, as a recent survey I conducted amongst my website visitors showed 27% of eBayers would be unlikely to bid in a private auction.

However, there are some very good reasons for using a private auction. Firstly, it provides privacy to both parties - the seller and the winning bidder. If your auctioning off something that may be considered embarrassing or perhaps something of an adult nature bidders may not want this item shown on their feedback profile. With a private auction, both parties can still leave feedback but the item number will be unavailable to click on.

Unfortunately, it may be sometimes necessary to run a private auction to protect yourself from other sellers. Many less than credible sellers have been known to poach bidders for their own auctions, using the contact member feature to alert members to their own auctions.

In some eBay categories such as the Business & Industrial, this is very very common practice. If you suddenly find a lot of bidders withdrawing their bids for no reason, it may be worthwhile trying a private auction.

Overall, there's no reason to avoid bidding on a private auction more than any other auctions. Just be sure to check out the sellers feedback first - if that's been made private as well then maybe it's worth having a second thought before you place your bid.