One great advantage to having a blog is that it notifies your web visitors that you are an expert. While your basic website gives an overview of your products and services, a blog can really dive into what you know in great detail. Businesses that have blogs look trustworthy and reliable.
Additionally, if you are using Twitter, you will soon find that it works hand in hand with a blog. When you post new blog entry, you can insert a corresponding tweet that deals with the subject you are writing about. Twitter will send web traffic to your site through your tweets. You will find that people who usually would have never visited your site are going there to read your Twitter posting. While you have these web visitors at your site, they can read about your products and services or perhaps sign up for your mailing list.