Well since this is the SEO section you will need to of course build links, but a braoder strategy could be one of volume, where you build out thousands of pages targeting longtail keyword phrases, as well as embeding video and uploading images with proper alt tags (images get searched a lot as well don't neglect them).
As the survey suggest, around the 40-50% traffic comes from search engines. So, SEO is the best. But it is necessary to see the seo as a whole process. Only one method from seo can't make much effect. From the front you have to do it step by step. You can also hire seo professional for that.
Fresh and quality content is a magnet for traffic.Start a blog and link it to your site,become an expert in your niche and share it via sensible blog comments,knowledgeable forum posts and great articles on ezine and article.Join Facebook Groups in your category and promote your site.
first select new keywords which are more related to your site and then you increase your keyword density by adding your keywords on title tag, meta tag and content. After that you should be do lot of Off Page SEO work for that keywords.