Your blog gives you a platform to create relevant content for your clients and prospects. If used as a marketing tactic to drive traffic to your website it can be extremely powerful.
Make sure that your blog is actually built into your website. If your blog is built elsewhere (perhaps on Tumblr, Blogger, or WordPress.com), then you may be driving traffic back to your blog, not to your website. Yes, I appreciate that you will start to appear as an expert in your field, but visitors will not have an opportunity to see what services or products you offer if they are not on your website.
It’s a well-known fact that the more people have to click, the more it dilutes the conversion.
Make sure your blog is on YOUR website – not elsewhere.