I never thought powersellersunite as being bias. Who cares if they have paid ads form auction sites. They offer free services and they need to pay the bills. Auction sites see it as an opportunity to reach sellers and buyers. Seems like both sides win.
I have not seen powersellersunite treat sites differently wheather they advertise or not.
Onlineauction isn't the only site in the auction site count with a banner. They might have the top spot but it doesn't mean that they are the biggest advertiser. Both Lowbid and mightybids have two banners. Mightybids is on the auction site count and so is bidville who is now owned by ubid which also has an add on powersellersunite.
The mods are volunteers and they need to make money too so I think its fine for them to promote where they are selling.
It makes business sense for an auction service forum to help people with auction services to take money from auction services otherwise that auction service forum wont' be around for long. Just as long as they don't favor sites and remind unbias whihc I think powersellersunite does rather well.