Wanna get a Great quality score for a keyword? Don’t just stuff that keyword into the title tag, headline, alt tags, etc. You need to think about other keywords as well – those related to the keyword you’re trying to optimize for.
What are they? Well, now Google kind of tells you, sometimes, with a new-ish feature that appears at the bottom of the search engine results page (SERP).
The "Searches related to: Keyword" section lets you know how Google is applying its latent semantic indexing algorithms.
In the example above, a search for shamanism is related to a whole bunch of keywords that don’t even include the main keyword and aren’t synonyms for it. A "dumb" search engine or keyword research tool wouldn’t be able to link shamanism to ayahuasca, or animism. Google knows this because it follows us as we search and re-search and re-search again, refining and varying our keywords until we get what we want. So ayahuasca (the "vine of the dead," a psychotropic plant used by Amazonian shamans to facilitate seeing into the spirit world) is linked to shamanism by virtue of iterative search behavior.
Once Google understands these connections, it looks at your web page trying to rank for shamanism to see if it contains any of the other related keywords. The more the page seems to display the correct context for the keyword, the more highly rewarded it’s likely to be.
So run your big keywords through the SERP and take a peak at the related feature down at the bottom. Then go see which of them can logically appear on your landing page.
(This insight comes courtesy of Search Engine News, to which you can subscribe for $144/year.)