To build and maintain a steady audience, regularly add new content to your blog. Every new blog entry should cater to your blog's target audience, offer content that's perceived as valuable, and build upon previously published content.
For a blog to be successful, you must stay on topic and cater to the wants, needs and expectations of your target audience. This means developing a thorough understanding of who your audience is, then adjusting your focus as trends and demands change over time.