We have been doing SEO for clients for over a decade now. But as time has passed a clear pattern emerged with Google and what they wanted. They want you to get your links from the highest quality sites, sites that they trust.
They want your linking to be natural, what they mean by that is natural behavior. Natural behavior to them of course is not natural behavior to the lay person. As we understood more and more the mindset of the people involved in their search algorithm we found an effective way of ranking sites and doing it in a way that met their criteria.
Our experience and constant testing will get you to the first pages that are relevant to your business.