Respond with personalised comments rather than a generic Thank You. Fostering a conversation helps build the credibility of your blog!
Use technology - Social plugins and SEO tools are a great thing to market your blog or a blog post. If you do not know about it, then learn it. It helps you reach out your audience in a better way and also improves the ranking of your blog.
Blog for the fun of it and show character. It is immaterial how many write about a particular subject, it is how you write the matters.