SMO is one of the parts of SEO, it is best increasing visitor. Social media optimization like facebook, twitter, linkedin, g+; it's helps you in building good social media reputation which is considered by Google while ranking your website in search results.
To increase the number of visitors of your site you will have to promote your site on various social media sites, create quality backlinks, and do press release for your website.
increase visitor own sites by the attractive content or title..something should be attractive ,and unique content..Social Media Sharing is also best way increase visitors.
Start doing SEO which consist off page and on page SEO. In off page seo, Directory, article submission,ppt submission,bookmarking are there. Which to increase traffic in your site. Regularly do off page SEO to increase traffic as well as for PR.
To increase the visitors on the website you need to improves your technique of marketing and techniques which automatically increase the visitors to your website.