Blog posts create more internal links to your website which helps a lot in SEO. Blog is a great way to have quality content on your website related to your products/services which is indexed by all major search engines like Google, Bing and Yahoo. The more original content you write in your blog post, the better ranking you will get in search engines. SEO is an on-going process and posting blog posts regularly keeps your site active all the time which is beneficial when it comes to search engine optimization.