Write the book that you have to write, but make sure that other people want to read it.
If you want people to buy a non-fiction book (not just when it first comes out, but for ten or more years) then it has to be useful to them. You must say *hello* to Little Miss Useful. Polemics sell well at first, but after a while the outrage diminishes and everyone moves on to the next big thing. You can make a living out of being controversial, but I don’t have the energy to go down that route (too much anger). Getting people to buy your book, and to keep buying it, is the hard bit of being ‘a writer’. So, how do you do that? Well, the most thrilling thing that ever happens to me as an author is when a teacher says, “Your book really helped me. It was useful to me.” It’s a bit like when the kids say thank you to you, as they leave your class, or as you leave their school. Hurrah! I have been Little Miss Useful. You bought my book and you got value out of it. My work here is done. To be ‘a writer’, you have to write things that other people will buy, read, and enjoy. Because then they will want to buy your next one. It’s as simple (and as complicated) as that. Write a book that you would find useful, and then hope, hope, hope that lots of other people do too.
“If there’s a book that you want to read, but it hasn’t been written yet,
then you must write it.”