i listen to audio-books bought online. saves time to listen books while doing other things. If a book is not available in audio format i get it on amazon
I bought some books from some guys here, and they were very useful. I work with the principle that, if you want information about something and you don't want to loose some time, than you have to buy it.
I buy books once-twice a year from Amazon. Too bad that, living in Europe, shipping rates are quite high for me.
I buy a lot of books from amazon. I pay £50 a year for that deal where you can get free shipping on most items.