Kinda looks like he leaves that kind of question to be answered by his ebook see here:

http://www.kreci.net/android/make-money-on-android/

http://www.kreci.net/android/make-money-android/

Which just goes to show he can do marketing on more than just android. I guess I'll support it because I really like these income reports but I can't comment on whether the ebook is any good.