Good day C.S.,
Unfortunately I have the same experience as you. If you are looking towards moving serious volumes, you will need to invest into marketing. I believe this holds true regardless of your audience size. At the moment, for 2020, I would suggest finding the best reddit area for you to advertise in. Alternatively, use your social media networking resources. Heck, dev has its own listing area on the front page -- list it there (I did). Beyond this, I would recommend finding an area where your audience hangs out and participate there. Or... you could write your book or an outline or a project proposal and work with a publisher.
Hope it helps.
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