What is the main purpose of the blog you write that?
Your question is not very clear.
Blogs can be used for lots of things. Infact the general ideas is that you do whatever you want with your blog.
Wikipedia is much detailed on the subject: http://en.wikipedia.org/wiki/Blog
You can also earn money from blogs through various technics.
I write blogs to share the personal experience and for expressing thoughts.I think blog is a mean by using it we can share our ideas with each other.Another purpose of blog is market your business.It is also used in internet marketing.
This topic has been, and is being, discussed in other threads.
Please Search using the vBulletin Advanced Search and SitePoint’s [URL=“http://search.sitepoint.com/”]Advanced Search