I think that the posts per user (to get more users to actually post and participate instead of just reading in which most poeple just read) would be a great way of making this site a much better place because it would make this site as good as if it would have two ore three times as many members.
Also one has to take into account that there are probably a lot of members that do not come on this site that often and probably quit coming on, and i would say that half of the members are not on, but also there are a lot more guests than registered users. Thats why sometimes hits count for a lot more than members because the number of members does not indicate how many people view the site and how good the site is. More people at one site might become a member than they would at another.