One more thing about Amazon - for physical purchases, the minimum total to qualify for free shipping always gets me to add an extra movie or book. They really are the how-to guide for selling online. I am far more likely to find a book I want, or discovered I want, on Amazon than in my local bookstore, where I can't see the virtual links between shelves and sections (liked this? 90% also liked that).
I don't believe book publishing is dying, but it is changing significantly. I hope the author's idea of market-drive, focus-group-suggested topics dies on the vine - that killed pop music for me, I don't want it to infect book publishing.