In short, I've been on this forum for ~2 years as a registered user, and read silently long before that.  I mainly sit and read, read, read.  Often, logged out.  I have about 14 posts, sporadically across the entire time period.

So this all bit me yesterday when someone I reached out to said "ewww, no, you're a newbie, go away".  I figured I had 1-2 posts, because I rarely am inclined to speak up.  But to my surprise, I have 14... and I've been registered for 2 years.. WTF?  I don't care about badges and stupid labels, so this "newbie" thing was not something I ever looked at.  It was a surprise to me that the system itself would try to scare off anyone I talk to via private message.

So I spend time to dig and find the formula, and it's all based on lowest common denominator of browsing-while-logged-in and posts.  You might consider factoring in years and frequency of posts?  Or using cookies more aggressively the way advertising companies do?  

Frankly, most of the time I spent browsing while logged out was DELIBERATE as a means of protecting the site itself from XSS attacks.  I didn't realize this would be held against me.  If I were properly credited for all the time I've spent on this system, I'd be one of the top ranks, not the lowest.