I can remember a time when we were scolding a certain seller for using eBay's private auctions. But as an eBay seller, I agree with many of Mike's points. I also suspect many people may feel freer to bid, and bid more, if their bidding habits were not such public knowledge.

Another "change" this would create in the eBay cycle would definitely benefit well known bidders. There are those who, rather than look through all the listings for the good chips, look to see what the knowledgeable chippers are bidding on.

The biggest stigma is whether or not bidders perceive something "shady" about private auctions, in the way some people shun and chastise reserves. I think if more of the regular sellers use this process, and bidders learn the reasons and benefits, it will be accepted. I think it really does aid in the process of what the auction is supposed to be. It's sort of like the issue of the hard auction closing time. Some bidders may like it because they can snipe and get stuff cheaper, but the process would be improved for everybody if there had to be an interval of no bids before an auction closed.

As for Trav's concern, I think it's valid, but secondary to the auction process. I think your best option is to email the seller and ask to have your email address forwarded to the high bidder, with the reasons explained. But for this and other reasons it puts more power in the hands of the seller. Bidders may see this as a threat, and hence the stigma. That's why I feel it is more apt to be accepted if more of the major sellers adopt it as SOP (standard operating proceedure). I will join in the experiment.