Campaign tracking codes can be useful for tracking the usage of your site during periods of time. There are numerous free and commercial services on the net to provide you with these codes and the statistical engines to visualize the data. One such engine is the free Analytics from Google. How to use and enable that service is beyond the scope of this help and the support of Atlas. But when you have enabled an account, on Analytics or elsewhere, and you have the campaign codes, you enter them in the module.