If you want to show off how active a site is to management, show them your "Active Topics" within "Past 48 Hours"
https://www.ubbcentral.com/forums/ubbthreads.php/activetopics/2/1

Or how many active new registrations your site has had within the past set period of time:
https://www.ubbcentral.com/forums/ubbthreads.php/ubb/showmembers/sb/10/page/1/like/-1
--especially OF THOSE new registrations, who've made a single post.

Or how many registered users have logged in within a set period of time:
https://www.ubbcentral.com/forums/ubbthreads.php/ubb/showmembers/sb/14/page/1/like/-1

Or how many registered users are currently online:
https://www.ubbcentral.com/forums/ubbthreads.php/online

But if you really want to show off the health of your forum, have management post a few random questions as new user accounts to your forums. Watch how quickly your community responds to those questions and the type of replies they are given. If nothing happens, and no one replies, Your community is near non existent.

And most importantly, just because people are able to find your content and they are reading it, does not mean that they are a community -- online and interacting. A thriving community of members tends to interact and help each other out with flowing ideas and conversations. These are the type of people who look forward to returning to your site day after day. The fore-mentioned type of people are most likely organically finding your site through a search engines and have no loyalty to return to it... especially if there is no community or deep substance to gain from returning.

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If you're not too worried about your community and just want numbers, install Google Analytics for some serious statistics:
http://www.google.com/analytics/


Current developer of UBB.threads PHP Forum Software
Current Release: UBBT 7.7.5 // Preview: UBBT 8.0.0
isaac @ id242.com // my forum @ CelicaHobby.com