Use social media websites like Facebook, Twitter, Youtube (check which one will work for your business, where your audience spends more time) and post regularly useful and meaningful information. If you use Facebook, you can post on different groups that correspond with your business niche. Try to engage your audience with interesting posts that they would like to share and eventually bring you more traffic. Pay attention to the time you post. Check at what time and on which days your main audience is most active and you can schedule your posts according to the information to increase posts' visibility.
Write Quality and interesting content. Engage with your audience. When people share your content with their audiences, it can help drive more traffic to your website and build your network on social media. You can also offer freebies and discounts specially for your social media audience. Hope this helps.
It is pretty difficult for business pages on social media to reach the audience. Even all the followers that liked your page may not see all the posts on their wall and only half of them may see it. This was done by Facebook so businesses would buy the promotions of their posts to be seen more.
The other way is to have high-quality content, that your followers share.