I've had a couple of comments that made more than almost all my posts. They were on a whale's post and they voted me up. So commenting is definitely worth it. It may also get you noticed by others.

I really value comments, otherwise I'm just talking to myself :) I've had great responses on some posts. Others have no comments, but still earn well. I think it can help to have a post with questions or to be a little controversial. I don't want to start fights, but discussion is good.

I had worried that edits would cost me. I sometimes only spot mistakes after posting and I like to fix them. Do all versions of a post stay on the blockchain?