Promoting your website to get more traffic need not be something you do on your own. If your site visitors like the content you post and keep coming back for more then chances are they've got friends or acquaintances who might like that content. This is why you need to ask your site visitors to tell their friends about your site, share articles they like on social media or bookmark your site if they can. There is no guarantee that many of them will help but how will you find out unless you ask them and keep reminding them to help you promote the site? There are some sites which relied solely on "word-of-mouth" referrals that now get tons of traffic every day. Your traffic could grow thusly too. Just ask your site visitors to help and hope for the best.