This is ridiculous. Does they not realize that you can do the exact same thing at a bookstore? I’ve sat reading entire chapters that way, yet still buy good books, technical and otherwise. In my pre-teen, pre-money days, I read a few books this way. Those were not lost sales for anyone, believe me.
I almost wonder if this is EULA-logic creeping into the mainstream: people shouldn’t be allowed to see something in full until they’ve already paid.
Coder to Developer sits on my bookshelf because I was allowed to look through it in full and weigh its quality.