Short is good. I've been working on my own creative commons book (4th edition of my Java AI book), and you have me at least thinking of segmenting that into several mini-books (search, machine learning, etc.).
FWIW, I've gotten more positive feedback about the length of these than anything else. It isn't "thanks for making it free", or "thanks for making it good". It's always "thanks for making it short!" :)
Karl, since this is already written in Markdown, have you thought about putting it on Leanpub? Our books are in Markdown, and we generate PDF, EPUB and MOBI. We support variable price and a minimum price of $0 if you want, so readers can pay whatever they want as long as it's your minimum price. Royalties are 90% - 50 cents per copy. Finally, readers get automatic updates if you post new versions etc.
Short is good. I've been working on my own creative commons book (4th edition of my Java AI book), and you have me at least thinking of segmenting that into several mini-books (search, machine learning, etc.).
BTW, I also liked your "Little MongoDB Book."