Thanks for posting the link to this. I'm happy to answer any questions.
1. Did you have to 'kick back' any money? To those that you interviewed, or companies where you used their screenshots in your examples/critiques? Did you reach out to them and notifying them that they/their company will be in your book for profit?
2. From the sample chapter, you talk a lot about principles and critiques of interface design but are there any area in the book where there are data or user ability studies to explain it further (ie: why they work)? Or is most of it based on experience?
3. Any plans for a sample page on the case study? I think that's where the most value is - the full process of where you take us through your thoughts and reasoning on designing a product.
For companies I didn't contact them in most cases. The few I did talk to were thrilled their designs were being used as an example in a book.
2. This book is light on data and studies. That's a short coming. These are all techniques that I know work well, but I don't always have a study to back it up.
3. I'm not sure what you mean about a sample page for the case study. To better market it? That case study has a lot of great content and I'll be working with the company further to write a lot more articles and tutorials around what we all learned in that process.
For the case study, basically I'd like to know what it entails before purchasing. All the other content speak of principles and guidelines but I find it more interesting to read about an actual case study, the thoughts and reasoning behind the decisions made. (I can't find what the case study was about too - just that it's a time tracking service. Is it Harvest? Basecamp?)
You said you'll be working with the company further, I look forward to that one!
I believe he's currently working on adding subscription payments (and hopefully invoicing) which I am very keen to get but affiliates/electronic delivery could be another great add-on for him to deliver.
More about that here: http://nathanbarry.com/commitment-changed-career/
Did you really make all of the graphics and layouts (perfectly I might add), create a book landing page, tweak your blog to promote the book, maintain your Twitter following, deal with miscellaneous tasks (server configurations, etc), conduct interviews, do the copyediting and review process, all while writing 1,000 words a day, in the same timespan?
Did you have a life? Did you ever take time to watch a TV show or switch off your computer or phone? Really inspiring stuff man, great work!