I've been doing lots of thinking about this recently. It seems like most people I know tend to buy online without a second thought and hardly ever go into the shops. If they want a book pre ordered they will just go straight to Amazon, when you can do the same at the shop, and the chances are that you will get it sooner.
I tend to sometimes buy online if I am wanting to do a bulk buy of books, just to make it a bit cheaper, or if I want books that are only published in America. I did last month get 6 books for about £30, which I was pretty chuffed with. The only problem is that you don't always get the cover you wanted. My Vampire Academy books are all different and I got them all off Amazon. Some are really gorgeous red covers, and the rest are the ugly covers with the creepy looking people on them. I sometimes find myself doing a quick shop online as well if it gets to about the middle of the night and I can't sleep.
Then we have the shops. I absolutely love book shops, they are my main destination if I am going into town. They might be a bit more expensive, but I tend to find there are more good offers. Waterstones and Smiths tend to do buy one get one half price offers, and The Works usually have some good books in their 3 for £5 section. I found Half-Blood by Jennifer L Armentrout in there the other day. I grab a loyalty card for any shops that do them too, and can nearly afford a new book on one of them. I love being able to support the shops and get to know the staff. Waterstones will always be my number one choice for if there is a book I really want.
Which do you prefer? Are you an online person or do you love the feeling of going in a shop and leaving with a book?