However, many businesses have had websites built that don't have such tools included. While incorporating a blog might not be impossible, it's usually not something you can do yourself. So you have to fork out more money to get this done.
If you're in this boat here's an alternative. Why not build a Google Plus business page for your website and use that as your blog? Doing this will confer SEO benefits anyway. And if you keep adding good relevant posts to it, well, that will help even more.
One of the great things about Google Plus business pages is that you can use them to participate in communities on the site. (You can't do the same thing with your Facebook page by the way -- although you can like and comment on other FB pages.)
Google Plus communities are really active and full of great people to connect with. I've found that getting involved in them is one of the best ways of building your follower numbers.
Now I know that lots of people here complain that there aren't enough Aussies on this network yet. But that is certainly changing. It's already second only to Facebook in sheer size, remember.
Anyway, you don't just go on there because it might get you some sales. You should participate in it to make quality connections. The benefits of these may not be immediate, but they are substantial and varied.
Speaking of connections and blogging: Linkedin is also rolling out its own publishing platform, which can be used as a blogging tool. Up until now only big time influencers could use it. But the plan is that all members will have access to it before too long. I think this could be a really good option if you don't have your own blog included in your site (or even if you do).
Linkedin is not as big as the other social networks. But it's absolutely chockas with serious, influential people. Publishing a blog about your niche might not get you heaps of traffic. But it would certainly be very good quality. And given the high quality social environment it's in, increasing your influence would happen more rapidly than if you used a traditional tool like Wordpress or Blogger.