I Like the Idea,
You obviously need more banner space to auction as at the moment the site feels empty , if you have any capital i suggest buying some sites with traffic and auctioning space on them
(maybe shorter than 6 months to get them back on the site quicker).
At least fill the featured auctions section and keep it quality in there,
As this is the first taste of what's on offer.
At first glance i can bid on a banner space from a phone type site with visitors of 3400 a month and the contract period is 6 months,
the current bid is $20
would that be $20 ( if won at that price) for the whole six months or $20 a month ?
If its the latter and the site had UK traffic,
i would theoretically be very happy to bid in this auction.
Talking of UK traffic, As the majority of domainers on here are intrested in Uk Domains and promote UK products/services. it would be quite important for us to know where the traffic is from, You provide a view of google stats of one of the sites your auctioning, maybe expand this further by giving people the option to add extra stats in the way of traffic origins and what keywords are pulling people to the site. I can imagine not all people would want to part with such information but i know as a buyer this would allow me to make a much stronger decision and therefore i would be prepared to bid higher