Some books are easier to buy in person than on-line. I find recipe books and children's books much more enticing when I see them and can browse through them physically. Other things I can do mostly on-line. For the most part the book stores are failing me because they have walls of Twlight and Hunger Games, but little for showing me the staff picks of if you liked this sort of thing.
So I do some shopping in person, but when I can head home and go to the Chapters.ca and buy the book I saw at the store for $20 for $12 and free shipping on orders of $25 or more, I tend to save up a few books and buy on-line. I'm pretty sure that model is a nail in the coffin of the bookstores, but then I don't think Chapters as a corporation would be sad if I spent $25 on-line instead of $25 in-store and just closed the physical store. Bad news for my city, but the writing is on the wall and has been there for quite some time.