Many of the big, private sales can no longer take place though. Or, at least, I would imagine they are much harder to achieve as the buyers can't make those threads as noted above.
If by "private sale" you mean not telling letting the buyer know what domain they are getting, yes... this is absolutely correct (at least in it's current form). But I've been thinking about ways to make an auction be able to happen without listing the domain publicly. Something along the lines of the seller still needs to verify ownership, but it wouldn't be shown to users. The seller could "pre-approve" bidders (once you are on that list, you can see the domain and/or make a bid). Something like that would make it so the seller could hide the domain, but also make it so they still have to verify they actually own it and bidders know what the domain is before they bid.
I wasn't thinking of domains, I was thinking more of services. But on what you just said, that sounds like a good idea. This would surely only work on 'high value' domains though, as the average buyer isnt going to want to go through finding out loads of 'private domains' for sale to find one they like. I know I briefly glance to see the domain before moving on if it doesn't interest me. Obviously this has its drawbacks as you'd need an individual (or group) to be able to establish whether a domain actually has 'high value' or not!
Right... obviously if the seller doesn't want to disclose what they are selling (or make it more difficult for the buyer), they are going to loose out on a ton of potential customers, but that's ultimately their choice. I *don't* see a system coming back where we let someone bid on something like a domain without the bidder actually knowing what they are bidding for though if that's what you are looking for.
Why did you mentioned the domain sale example, when the domains "sold" here are so poor? Here are the current domain on sale at the marketplace: http://img255.imageshack.us/img255/3041/dp1n.png http://img89.imageshack.us/img89/2992/dp2v.png http://img42.imageshack.us/img42/6615/dp3s.png How do you know what and how much were sold things before when you had no control on sales?