When it comes to search engine optimization not everyone is the same or has the same process. The results that everyone wants are the same but the road to get there is different.
There are many factors that come into play when doing SEO and each one adds to the whole of the project. If one of these pieces is out of place the whole machine may not work and you will not be able to rank your site.
If you have a keyword too many times on a page or in the title or in the links coming to your site it will hinder your process and may get you a penalty from Google causing more headaches than you thought possible. Be careful.
This is why you need to hire a professional company to handle this for you.