Prior to writing my first book, I already published quite a lot of articles, so I knew that there was some non-empty audience set out there :)

I started a crowdfunding project for the first book too, so that the printing and typesetting costs get covered. They were covered fully, so I knew that I won't dip into red numbers as a consequence. (This was a major worry of mine.)

I was still pretty nervous about acceptance, but it turned out OK. Whew.