I've developed the following formula based on my own experience:
CGB contribution = (120mins/story * (Numbes of stories) + 30mins/fanpost * (Number of fanposts) + 15mins/fanshots * (Number of fanshots) + 1min/comment * (Number of comments)) / Number of days since joining CGB
Each coefficient is based on the average time I spent developing stories, fanposts, fanshots, and comments.
The following is a contribution snapshot of CGB mods & Hit Squad on Boxing Day 2010:
Click here for a larger version. Misc column sums up CGBers' Fanposts & Fanshots posted on other SBNation blogs.
TnH leads in mins/day at the moment but Avi is catching up fast.
Atoms is doing quite well providing commentaries only.
Yours truly is comfortably contributing less than 10mins/day to CGB.
How much time do you contribute to CGB on a daily basis?