Stephen King has nice article about the Harry Potter books here where he critisizes the critics reviews of the latest book of being made on a very hasty reading of the book in order to be first to publish a review.
The hasty reviewers , according to King, do not get the full benefit of the book by such a fast reading. I tend to agree.
Further he talks about the appeal of the books to children and adults alike, and stresses the develpoment of the main characters from children into young adults as an advantage of the books , the young audience grew up with the characters. Good point.
Finally he noted the magic of the books that keeps the children interested in reading, clearly showing that the (paper) book is certainly not dead, even in this age of electronic media.
Read the article and decide yourself.