The trouble with average karma is that it penalizes people for carrying on conversations. I often post something that has 10, 20, or even 50 points. Then someone replies, and I reply to that. This deeper reply will almost always get only half the karma of the original. Possibly because it is less interesting, possibly because it is posted later in the life-cyle of a submission.

If average karma was a goal of mine, I would never follow up to my own posts, I don’t think that I’ve ever had as much karma for a follow-up comment as for an original.