CMDA
I thought the presentation about CMDA was very interesting! I LOVED my linguistics course as an undergrad, but never thought about applying it to my online community! Interestingly, I DO have logs of my guild members' activity that we can see as members of the guild. You can see how many times each person has posted, when they joined and when their last post was. Quantity of posts alone isn't enough to tell you about a person's participation...but if you pair their number of posts along with how long they've been in the guild and when their last post was you CAN gain a more accurate picture! For example, realising that a person who's been in the guild for over a year should have a LOT more posts that someone in the guild for a month...and if they havn't been there in over a month? Usually we know eachother well enough to know WHY someone hasn't been there in so long...otherwise we contact them with a friendly "how's it going" mail.
Secondly, images/graphics etc DO play a HUGE role in our guild! We have graphics at the guild itself (that we let various members contribute to) and we also have a separate info page. Your design DOES communicate something about your community so it is important if you want to bring new people in!