Having been involved with SEO in various roles over the last 10 or more years, I’ve had my fair share of conversations dealing with a wide variety of theories and hypothesis concerning the best approach to a company’s SEO efforts.
From in-house SEO to outsourced SEO, I’ve seen SEO efforts range from being planned, implemented, executed, measured and sustained flawlessly to those SEO efforts that were DOA or dead on arrival once the SEO efforts were executed. I’ve also seen and experienced mediocre SEO efforts.
My point is, there is no one-size fits all SEO effort. Whether in-house or outsourced, consider your SEO effort to be unique in its own right.
That’s not to say you should not focus on SEO fundamentals, but it is to say that you should always enter SEO knowing that there is no guarantee either way.