I second that. Who needs em? Problematic admin, no traffic. That's all they are. Remember microsoft's banner exchange? Where is it today? In a recycle bin somewhere I expect.
Nothing wrong with banner exchanges and they dont run out of steam as long as you place the banners well on your site and use a banner exchange who give credits for clicks as well as impressions.
However, you will not make enough revenue to pay people for their clicks etc, and also you are leaving yourself WIDE open to fraud!