How would you like to have free traffic for your website? Suppose your website is on cab services and if someone searches cab services on Google and your website comes in first page, then your phone would start ringing at regular intervals.
The key to rank higher in search engines is links and more the number of links to your website, higher your website would rank in search results.
I learnt SEO all by me and my site kalkie.in used to rank #3 for keyword VC funding. My expired site igurucool.com was #4 in Google for keyword online tutor. Some freaky guy put thousands of back links of these two sites on negative sites and my rankings disappeared.
I can again rank my site