Adding content to a website in general can help improve it's rank in search engines like Google, so it follows that having the ability to add content - and web pages - fast is a great feature for your website. Blogs make it simple to add content to websites, making it easy for you to improve your website's search rank. You'll need to choose which blog program to use on your website, and fortunately you can get some extremely high quality blogs for absolutely free from open source websites.