I have an ad delivery system I built with plans to open it to general use. I used it with affiliate links on about 200 of my own websites. The ads are text, similar to google ads, but not anyway close to as good.
I remove the ads and left just ads for my business because the affiliate links were too much to maintain for the income they generated. But the system allowed my to deliver text ads to hundreds of sites from one common point.
I still have some automotive ads at:
You will notice the ads on the right side of the pages labeled at the bottom "bulblebee ads". They are java script delivered.
If there is a significant amount of interest I might be willing to finish the development and open it as a ad exchange system. There are already ads on at least 150 of my websites to get started.
I also run a hosting company, so I have many clients that may be interested in joining and its been an idea on the back burner anyway.
Unfortunately, I do not have any fraud controls, so we would need honest people that would be fair about traffic.
I do not have anything to show as far as the management system, because I have only used it myself. But I thought I would throw it out there into the discussion.
I just built a program to deliver my clients ads to parked pages. Another heavy resource I have. Hundreds of parked domains.
I would be interested in advertising my hosting service on any small business websites that might like to exchange ads. Just need a fair way to exchange traffic.