This article was interesting. More than 170 authors have sold at least 50,000 E-Books.
Before the Internet, if you wanted to publish a book, you had to go through the State gatekeepers. You send out manuscripts, and hope some publisher agrees to print and promote your book.
With the Internet, the gatekeepers use less power. If you publish an E-Book or use a print-on-demand service, you can bypass the State gatekeepers.
It also allows more niche books. A publisher wants a bestseller or potential bestseller. The State middleman has many employees, all of which must be paid. As an independent author, 50k sales is enough to pay your salary.
I’m filling in the posts and my FAQ section. That will be the starting point for my book attempt. I don’t expect 50k sales, although that would be nice. If I can make $240, that covers my Linode expense for a year, and that would be clearly better than putting up spammy ads. If I can make 10k-20k+ sales, then I could consider doing it as a job.