It was the penalty/bonus threshold. Steemit said that it would be around 20 STEEM, but it turns out that the bonus/penalty begins somewhere around $10 in post rewards, which is quite a bit more than 20 STEEM.
This would be a great idea, in my opinion, but only if community voting was equal between all people. I believe this threshold concept doesn't work because of the disparity of vote values.
it is at 10$ you say? mhm, I see