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.
Its not just good content that matters, presentation of post is very important too. Have attractive pictures, fonts etc to hook the readers.
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.