Privatus Analytics
Ad experiments: test your own banner ads
Rotate your own banners, a sponsor's or a call to action in a placement on your site, and see which creative gets the most clicks. Impressions, viewable impressions, clicks and click rate are counted without cookies, and a creative the page hides is never counted.
An ad impression counts as an event, and a viewable impression or a click of it is never counted again. Sponsors get a report link of their own.