Promotion. I'm convinced the key to promotion is simply to not care whether anyone buys your books or not. In the weird way that these things work, I suspect the harder you are to find, the more people will seek you out.
It works that way in everyday life.
If I go sit in the living room, available for all and sundry to talk to me, no one will be around. The kids will find something to keep them busy. My daughter will take a bath. The son-in-law will play a game with the house hunk.
However, if I pick up a book and retire to my office, it's an iron clad guarantee that every single one of them will need to speak to me. That is the way life works.
Why should it not work in the world of selling books? So based on the basic premise, I should retire to my office and write books. Write, write, write and let the readers find me based on my writing instead of my promo. If I'm reclusive enough, people will seek me out.
My new motto? "Run and hide."