If you already use Google Analytics on your website, we strongly recommend you add a "click tracking" code to your banner's click destination. Doing so will allow your own internal reports to track clicks. Most clients use their internal numbers to compare with the click counts we'll supply you.
For those of you from the magazine world, these codes are akin to the "extension" numbers you used to place on magazine print ads; where the extensions actually just recorded activity.
Here's the link to use:
Might have moved here:
Download the attached PDF for a quick summary on how to use Google Analytics to track your visits through our ads: