Adventures in Self Publishing - Amazon keywords revisited

Some updates on what I've learned about keywords in Amazon.  From what I can tell, the search results are based on:

• Title
• Subtitle
• Series Title
• Author 
• Publisher
• Category and subcategory
• Keywords

Period.  Not descriptions, despite what I might have said earlier.  Also, the keywords are very flexible.  I never get my boolean search operator whatevers right, so I don't know the right word for this, but you probably don't either.  In your keywords, if you have a phrase or even just several words separated by commas, the search can find it even with just one word there.

My example:
Victim City Stories Issue 1
Category FICTION > Crime
Category FICTION > Mystery & Detective > Hard-Boiled
Keywords: Pulp, Masked Hero, Slasher

The book shows up under searches for:

• crime slasher
• "masked hero"
• masked slasher
• masked slashers
• pulp slasher
• masked crime
• masked (on like page 20)
• masked victim
• victim pulp

Note that "masked" works without "hero", so any combination of any part of the elements will give a return.

It did not show up under:

• mask slasher, masked criminals - the search is fuzzy enough for plurals, but not a whole lot else
• victim pulp crime masked potato - though it did pop up below the "no match" dialogue
• "victim pulp" - if there are quotes in the search, the keywords need to be in the right order
• masked protector - a phrase from the product description but not in the keywords

Amazon does allow phrases in the keywords, so I would suggest going a little crazy there.  There is a limit of 400 characters, and I wouldn't be too spammy - "hot sex naked steampunk Harry Potter billionaire game of thrones leaked nudes" - Amazon may eventually crack down (or not - the unofficial standard may just be 400 characters and they don't care how many terms you cram in), and the Harry Potter bit will actually get you a "no-no" email from Amazon.  But I think it would be fair to do something like: "mythological centaur horse person, curvy plump big boned large healthy bbw, rich wealthy billionaire millionaire".  Arguably, you could get rid of the commas altogether and have one big keyword string, but I like to at least pretend to be following the spirit of the thing.

With this in mind, I'm going to drastically alter my keyword strategy and see if that does me any good.