I have no limit. The idea is to set achievable goals and aim higher in the process. I have in mind that no threadcast should have less than 100 comments because I had one with less than 100 comments probably because I haven't replied to a few comments.
I know it can be doubled or even more.
That is true. Going through the notis can add to the counts when something its a day or two old. This is where we see the numbers adjust. I am going to start tracking the weekly threads/comments in general.