Traffic to your site comes from two main sources: search engines and partner sites. The best and most efficient source of visitors and potential customers has been and will remain the search engine that sends 90% of people interested in what services they offer.
Most services promoting have the same goal, and namely, to grow site positioning in search engines with as a site is better positioned in results with both success and profit or is greater.
A good positioning in search engines depends on many factors such as site content, but and how was developed site and allows search bots to access its contents and to some extent and links to which benefit or we doing on other sites.