SEO and SMO

Thinking a lot about Search Engine Optimization (SEO) and Social Media Optimization (SMO) lately. I came across this phrase (not sure of the author).

Is it a "how to" or a cause and effect? Or both?

search engines discover new content via LINKS
LINKS are signs of TRUST
TRUST can aggregate into AUTHORITY
AUTHORITY can influence RANK
users associate RANK with QUALITY
TRUST + AUTHORITY + RANK + QUALITY= Relevancy
RELEVANCY is a key factor in conversation.

I tend to be idealistic when it comes to the SMO side, from my experiences and observations. I don't feel like a step can be skipped, unless you want to cheat yourself. I think SEO needs SMO to be most effective. SEO doesn't make anyone real, though it may help improve sales. Can you really preform SEO without SMO and expect stellar results? I'm not sure, enlighten me, please!