To give some insight as a newer member who has yet to hit 60 posts... I don't want to get to 60 by spam so I try to contribute, but it sucks not being able to really use classifieds. I think a time based approach is probably best because it prevents people signing up, spamming 60 posts and then using classifieds. To me there is no difference between someone who has been a member for 30 days or 7 days or whatever, and someone who is a member and spams 60 posts immediately.