[tep]

"* It completely ignores people that read the post but didn't vote. There really is no way to get a perfect count of this no matter how much scroll logging, but you could approximate it and then include it in the calculation."

Would it help if there was an incentive to vote? You could, for example, increase a user's score by a point for each vote given but weight the vote with more points. This way user who write good comments and active readers could benefit.

But then again, this could tempt some users to abuse the voting system. I can't predict which of these two reactions would prevail.