I think it's a good idea, I've thought about it myself a bit. I'd definately check it out, but I think you need to work on the design, (ebay it up a bit) First I think it needs more advertising space, maybe 3 or 4 button spots accross the botton or down the right side. And that big chunk of space in the middle I think could be better used, maybe a couple large screencaps for featured items, or big ticked items.
Just my to cents
but I think it could be pretty good!