One woman said she looked up "Marketing for Introverts" on Google and found me that way. I took a look, and it was my Kindle title by that name that currently comes up first on Google.
While I'm selling those $2.99 Kindle books steadily to people all around the world, it's also very nice to get consulting/coaching/course income from that listing as well. This was my first direct evidence of that fact.
I encourage you to put important keywords into your Kindle title for this reason.