I have seen a couple of site which has high number of hits. They are mostly tutorial sites and blogs that address software issue/errors. I wonder if the kewybord "blog" has a very positive effect in SEO?

In my own site, I have install word press in root folder to avoid any blog keyword. I also did this to keep urls shallow (deeper url are not good for SEO). But I may want to think on it again. The sites I am referring too are

http://blog.sqlauthority.com
http://veerasundar.com/blog/2011/11/making-xampp-to-serve-any-directory-outside-htdocs/

I know there are standard (sort of) class names or ID that identify different contents and makes it easier for the search engine to identify contents like, "container", "menu". The use of word "blog" would mean this is about dicussing/tutoring something and have a very positive effect on SEO?