Users Recently Active counts the number of users who have logged in to the forum within the past 60 days.
We have just over 850 users who are fully registered (the 1180 figure for members includes members who registered but never activated their accounts plus members who no longer visit the site and their email address is no longer active - they get deactivated) ... so having over 50% of our fully registered members being active is pretty good I think. That's certainly much higher than for any of the other forums I run.
Why would snowleopard would be curious about this too ?