Iceland
If every person in Iceland bought your product, loved your music, read your book, would it be enough?
Iceland has a tiny population, but if you had all of them, would it be enough?
Of course, you don’t have to go to Iceland to get 320,000 customers. Geography is just one way to seek out edge cases.
Most successes aren’t the result of trying to be a huge success and settling for what you get. They are the result of focusing on exactly what you need, and getting it.