[lmiller1990]

How is your network? I wrote a technical book, I have around 1k twitter followers, a few hundred people on my emailing list. Each month I wrote a chapter or so, and sent it to my email list, and shared on twitter, etc. This is known as marketing. When I released the book, I had a ton of interest and I've made around 10k since release (15 months ago). I sell via Gumroad and have a membership ($100 / year) so they only take around 2.5%, I keep the rest. I sell for $30 but have many vouchers for lower income earners/countries, so the average sale price is around $15.

If you are not actively marketing and/or are not targeting a niche, no-one will buy your book, since it won't stand out among the hundreds (or thousands) of others.