When I first read Half blood prince it was in my computer ..I admit...the rest is strictly confidential....but
later my sis brought the book at a reasonable price for us...it is a win and win situation..we both benefited from both of them...this is my opinion though...

But what J.K rowling trying to say,is correct...paper is much better than screen...you dont need to strain your eyes in front of the computer all day...