You can tag your on-site ads campaigns clicks using the parameter xtatc in the query string of the destination page. The click will then be counted upon arrival on the page, much like the behavior of marketing campaign parameters.
Here is an example of syntax:
http://www.site.com/?xtatc=INT-10-[format]
or http://www.site.com/?xtatc=PUB-[campaign]-[param1]
This parameters also works when using an anchor #.