but it's always possible to create a natural posting rate of 50 - 100 posts per week if they spend more time on forum than in the real world.
Yeah, I agree with you that it's very possible to create 50-100 posts per week and many people make above 50 posts per week. Actually, I'm among those members who spend a lot of time on this forum and I make 40-80 posts per week myself.
Sometimes we get involved in some threads so deeply that it will be a natural flow to make that number of posts per week. I have seen members who make more than 70 posts per week and all of those are reputable members of the forum and their posts are highly constructive.