Introduction to Keywords via Understanding Searcher Psychology

So far in this SEO for non-scumbags series (first post and index here), I’ve spent two posts making the case for SEO to a skeptical audience and laying some strategic groundwork. Now it’s time to talk specifics and move to the more tactical.
In this post I’m going to cover what I consider the most crucial aspect of SEO, but one that people largely ignore in favor of stats about keywords. I’m going to talk searcher psychology. Specifically, I’ll talk through which keywords you’d want to tackle and why.
What is a Keyword?
First, though, some housekeeping. The word “keyword” sees a lot of play in SEO circles, but what, exactly, do we mean by keyword?
That part is simple. A keyword is the term that someone types into the search engine (or URL bar) when executing a search.