It's all about the stats.

Speaking of which, major publishers claim that only 18% of people who buy a book actually read it through to the end.
That's actually pretty sad if you apply that stat to medical books on brain surgery, or instructions on how to fly a Boeing 737-Max.
I'm sure it applies more for people who just buy something popular on a whim.
So yeah, it makes me wonder whether people who buy my book have the endurance to read it through to the end. It's definitely not a light read. Guess I'll know more about that someday as well.