Feedback for ebook on subscription billing

I have been thinking to write an ebook around billing for saas, to cover the different models, its challenges, the dos and donts and more.

I have been working with subscription and recurring billing for over 15 years and I believe i have a lot to share in this area.

The target group of the book should be mainly founders that want to go beyond the simple recurring billing model. It should be useful during the early stages for things to have in mind. It should be also useful once the saas is established and you want to start fine tuning the billing part.

Of course I will be writing this in public, and this is the first step.

I would like to have your feedback, is this something of interest first of all? If yes would you mind sharing some of the pain points/edge cases that you may have faced with your saas business? What you would expect to see in such ebook?

Thanks!