To monitor how many contacts click on the main Call To Action in a communication, you can mark the link to track a simple conversion.
To do this, open the link creation or editing page and select the Track a direct conversion option.
Conversions tracked through the link are counted in the communication report funnel, along with those generated by conversion goals.
The funnel adds together simple conversions and conversions tracked through conversion goals, displaying the combined result in the stage labeled Conversion Rate.