Joel Oleson is suffering if you do not blog ! Sounds strange ? Read the article Join the SharePoint Blogging Revolution!
at http://blogs.msdn.com/joelo/archive/2007/05/25/you-don-t-blog-i-m-suffering-because-you-don-t-blog.aspx
He makes several very good points - which have very little to do with Sharepoint - but I think the best one is helping the "organic indexing" of the Web space and helping the search engines out there better rank content. I wrote about this while ago.