Well, if we make that a metric, it'll be gamed, no? Don't track that at all. The advertisement should run for a set amount of time, and the correct metric to tr

Well, if we make that a metric, it'll be gamed, no? Don't track that at all. The advertisement should run for a set amount of time, and the correct metric to track is successful leads that originate from the campaign, which is easy to measure if you're tracking leads (you really should be) and the campaign has a unique landing page. Don't bother to track ad clicks (because they can be gamed) and don't sell ads based on clicks (because then they WILL be gamed) and the problem vanishes. Click fraud is a problem the advertising industry created for itself, and other advertising mediums without invasive user-tracking seem to get on just fine without it.