Social media is a good way to spread the word, but first you need to make sure you're delivering solid content and that search engines see you as an authority. The majority of new traffic to a site comes from Google and Bing. Sign up for Google Webmaster and from there you'll be able to see if you're getting indexed and what keywords people are using to find your blog. You may be surprised to find that you're not attracting the audience you think you're attracting. Good and consistent content is key.