I think you need to give away enough that people who want the entire book know they are getting something worth paying for. I have been disappointed too many t

I think you need to give away enough that people who want the entire book know they are getting something worth paying for. I have been disappointed too many times buying a fully locked down book to discover it's not as useful as thought. Obviously there are some well known/recommended books that overcome this, but it's chicken and egg for a new book.