How has the "pay what you want" model worked out if you don't mind me asking? It's something I've thought about in the past for selling courses.

I just changed the payment model before posting it here, so there is no past data on this. I don't expect it to generate revenue compared to normal sales (it will most likely be a small fraction). But for normal sales you need to be able to promote it.

My primary motivation is to share the work that I spent a lot of time on because I want to move on and work on other things (I don't want it to just sit on my disk when it can be useful to others before getting outdated etc.). It never was meant to be some primary source of income. In that case I would be writing a book about AI :)

Maybe I will write a blog post with some reflections about making the book at some point :)

I admire your mindset (and humility). Thanks for making this available.