I just bought David Goldberg's "The Design of Innovation," (his book "Genetic Algorithms in Search Optimization and Machine Learning," is an exemplary piece of technical writing). On checkout from Amazon, I was asked if, for \$$16, I wanted to upgrade and get digital access to the book's content. (It's a \$$68 book.) I said "yes," to investigate this new feature. It is not worth it. Look at this screen shot of the 200% zoom. as you can see, the text is bitmapped and hard to read. (You can even see noise from the page background.)