This traffic source comes from search engines like Google, Bing, and Yahoo. Remember, paid search ads or PPC (pay-per-click) advertising are not included within this source category. If you choose to run a paid advertising campaign for your business, it will not affect your website’s ranking within an organic search. Organic search is obtained through natural placement on search engine results, without paying for it, through search engine optimization best practices.

I'm not in the contest, but if I was - I'd be SKEEEEERED. This was awesome, really - there were MAYBE 3 things I knew... The rest was new. I'm lame that way. The great thing about this is that as a blogger - you've covered ideas I've never thought of...I get my traffic mostly from SEO (not on my blog, but in my websites which are product based review sites) - but there's enough meat in this post I can use for my niche sites to keep me in the black, so to speak (ink I mean, not socks). Awesome post, Brankica - I'm speechless. (If you ignore the foregoing paragraph.)

If you want to drop from your hard worked #14 position to #79, you can start looking for companies that advertise themselves like the one in the image below. We don’t even know what to believe when it comes to companies that promise guaranteed instant traffic: that they are folly (in which case you don’t need them) or charlatans (in which case you don’t want them). If you want to find out more about SEO agencies and how they can ruin your website’s traffic, we wrote a previous blog post on this. 
Otherwise you might end up polluting your website’s traffic. The pages filled with obsolete or low quality content aren’t useful or interesting to the visitor. Thus, they should be pruned for the sake of your website’s health. Low quality pages may affect the performance of the whole site. Even if the website itself plays by the rules, low-quality indexed content may ruin the organic traffic of the whole batch.
The term “organic traffic” is used for referring to the visitors that land on your website as a result of unpaid (“organic”) search results. Organic traffic is the opposite of paid traffic, which defines the visits generated by paid ads. Visitors who are considered organic find your website after using a search engine like Google or Bing, so they are not “referred” by any other website.