If you have watched the SERPS (search engine results pages) over the years you have seen that a number 1 organic ranking has gone from # 1 to something like #20 after all of the ads and what not that are shown above the first organic rank these days.
Some evolution images and stories: http://searchengineland.com/evolution-google-serps-three-key...
It is still "free" but takes a lot of work to get there, and it is worth less than it used to be. Lots of SEO's have gone the way of paid.