The subscription model gives you access to the drafts of the chapters and full book access at 8 months. For $9 at the lowest subscription grade this is $9x8 = $72 which seems like a fair deal to me when going through amazon for similar subject titles.

My experience of speaking with authors who have published books is that most of the money stays with the publisher and not the author which is a real pity. The net effect is the discouragement to write books which is counter to progress.

The subscription model is really interesting to me and I hope it makes a difference to the book publishing paradigm.