Because I check profiles profusely, I've noticed that when a person looks at a thread too long, or when they have remained idle for a long period of time, they're not on MT anymore. Minutes later their name will disappear from the bottom.
More guests read more Off-Topic discussion than RH.
(from my observations)
Some users (mainly noobs) only post in RH Forums.
Some users don't post in General Chat at all, or very seldomly.
Jonathan, Dylan and Roger are the only Mods who appear online when they're online.
Some users have been here longer and have less posts than newer posters.
I'll name more when I think of any...