I am guessing Igor is pointing out that for similar content, including educational material and answers to posts, scene files etc. one has to pay membership on gsg which is significantly more expensive than seeing few ads here and there, or possibly contributing by small amount. Now when I am not the owner of site I can freely tell you it is quite expensive to run and only thing that is holding it in existence is enthusiasm of owner and few members who are contributors. Advertisements and banners barely cover for price of dedicated server and security services. Hosting, backend administration, forum software itself, addons, domain....there is a lot more to cover :)