The real question is why do you give a shit? It's some algorithm involving all sorts of stuff. No two members use this site the same way, so no "value system" is going to accurately reflect the quality of a member's contributions.
There are people here who don't add pics, videos, articles, reviews that make some incredibly thoughtful, respectful, insightful posts who in my eyes are worth ten kids who post every pseudo-artsy dslr pic they take at their flattish icy mountain.
If you're in a thread and you look at someone's karma before you respond or interact or whatever, you're doing it wrong. I don't ascribe any significance to the number for many reasons not the least of which being that the calculation and even the system itself has changed half a dozen times. Usernames and icons make an impact on me, as in, people who have consistently made good posts over the years are the top members in my eyes, not the people who review every ski sock, face mask, and sticker pack they buy.
It's not "fair"....and yet, why are you riled up about it?
