Best way to log clicks on a link of a custom content type
A possible alternative to "record the clicking of such link" is to use the Message module to create a message like so:


Date = date the link was clicked.
User target = the user who clicked the link.
Message type = something like "Link of custom content type clicked".
Message text = whatever you want and possibly using "Replacement tokens" to have any of the tokens that you have available in your rule also included in your message text (should you have any such need).


Since messages are entities, you could add any additional fields you may need to complete such custom logging.

With this approach, you've reduced your question to (eg) creating an appropriate view (and/or chart?) of all such messages that got created.