Why Blogs Work
Blogs started out as simple Web Logs - short articles that were organized by date, categorized and tagged, and provided the ability for readers to comment and interact with the blog author.
My how things have changed. Many websites are now one part static content / nine parts blog content! Why? Each new article that you create as part of your blog becomes a new page in your website. And new, fresh pages in your website that provide content relevant to your service is highly valued in Google's eyes.