Engage readers with well-researched and creative blog posts. At the end of it ask questions or feedback from them.
Put advertisement but make sure that your blog visitor doesn't get irritated when ads pop up one after another like a flood.
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.