I just completed another article for the Marketing Lady on why it's great to blog!
Brilliant client who offers a great service which you should check out.
Setting up a blog allows you to showcase your expertise, no matter what line of business you are in. However, you need to make sure the content you offer people in your blog is interesting so they come back for more.
Algorithms are changing all of the time, but the one thing that remains the same is that content in king of the internet, not forgetting that images too are an important part of your content - but you need to make sure any photos used are royalty-free or you might end up in a bit of copyright hot water.