It’s Free- Natural results are listed based on the search engines measure of your website quality and relevance so you do not have to pay for ranking.
Long Term Rank and Traffic- Search engines record your ranking history which helps to improve your rank in the long run. The search engines also allow you to maintain your rank longer because they re-evaluate your rank every few weeks or months.
More Traffic- Currently it is known that approximately 75% of the searchers click on the natural rankings because they tend to trust the organic searches more than the paid searches.
Educated Visitors- Research has indicated that people who click on the organic searches are more educated.