Karma is really a "black swan" thing: sometimes you get one or two points, sometimes you lose a point because people don't agree with you and downvote you, and

Karma is really a "black swan" thing: sometimes you get one or two points, sometimes you lose a point because people don't agree with you and downvote you, and once in a while you post something totally innocuous (but potentially well-informed) and suddenly they're all over your post and you get as more upvotes than for all these carefully-formulated snippets of distilled thought. The community quality is, IMO, helped by the fact that there are dictatorial interventions to prune the few trolls that can survive in a karma-based community. (The legend is that some people are made to live in their own editorial padded cell where their HN posts can only ever be seen by themselves).