Have you ever thought about devoloping a script like http://www.Blogger.com/?

I am sure that many GT webmasters would like to buy such a script, because the concept is quite effective:

As more blogs (are set up by users), as more content (the site of the webmaster has), as more visitors (use the site of the webmaster), as more blogs (are set up by users), as more content (the site of the webmaster has) and so on...