Some ppl join a forum, make a post, lose interest or just don't visit again. They're still members and may come back one day.
We often have members returning to TamaTalk after a very long break from the site.
Others join TamaTalk and spend more time in TamaCHAT, so they don't have any posts on the forum.
Others, still spend most of their time in the Role Play forum. Posts made in RP do not count towards your total posts.