How to calculate engagement rate for Discourse?

It would be helpful to have an official Engagement Rate.

It could be applied in two ways:

  1. for users
    • Trust Levels do this of course but aren’t very granular
    • Perhaps a score based on TL?? e.g. user is new, just read 3 posts = 0.3. Highly engaged and well on the way to Membership = 2.7
  2. for posts / topics / categories
    • such as what LinkedIn etc do