CliqueSite.Ads Beta 1 available for download
This version will time bomb on July 1. So far I've been able to tweak it to the point where it can easily serve about 1.5 million ads per day on mediocre hardware, so for the bulk of future customers that need only a couple hundred thousand per day, this will take care of you, no problem. I've been running this on my production sites doing around 150k impressions per day, and that's on the same box as several forums, content management apps, SQL Server on the same box, etc.
I'm not sure how it will be priced, but I'm certainly open to feedback on that.