I’m gonna say my top non fiction books are:
The Narnia series, who knew that lions could be found in seemingly ordinary closets! Wow!
Harry Potter series, if I had known about hogwarts before i went to college I would definitely have applied there.
And then probably Wikipedia, man there is a lot of info on that book
Also because valve is private, they don’t have any legal obligations to return maximise profit. They can purposefully lose money if they want and it’s not illegal. (At least to my knowledge)