Well, yes, I would think that anyone who is primarily selling would want to keep his feedback centralized. But another thing is that the whole system depends on the buyers as well.
If I wanted to create a new account for selling stuff, I would have an incentive to go to the largest site that attracts the most potential buyers. But if I want to buy stuff, I also want to go to where the best deals are to be had. Again that favors the larger system as there is a better chance of finding deals. However, the reason that I favor ebay over yahoo is that yahoo has that thing about not actually closing auctions if there is any bidding near the closing time.
Of course if yahoo wants to be known as a “seller friendly” community that is their choice. But that makes it harder to get the best deals there and that is going to bias the community toward the professional seller who wants to make the most money.
However, by allowing snipers Ebay is more open to the bargain hunter. It is of course more of a risk to the seller but sales volume probably counts more than the occasional loss to sniping. Then too, if you have a house full of stuff and you want more cash than you can get from having a tag sale in your front yard, do you care all that much if someone only pays half to three quarters of the retail price for a given item?
Also, if a seller wants to minimize losses to snipers, they can manage their auctions by starting them at a fairly high price or by insisting on usurious shipping charges. That tends to discourage the snipers but at the risk of not getting buyers in the first place. Yahoo on the other hand automatically protects sellers by holding auctions open if two or three people are really trying to win a given auction.
