I know, I know, you don't judge a book by its cover. I've heard the phrase a thousand times before and in some ways I agree with it. Clearly the quality of a book is found within the pages, the story, the characters, the prose, etc, which makes the book's cover, for all practical purposes, irrelevant. But in some ways I think a book's cover is critical to its success. Face it, when you're in the book store walking past the display tables certain book covers catch your eye. Maybe it's a picture of a place you've been or maybe it's just a very interesting picture, but suddenly you find yourself with the book in your hands, you turn it, and you read the back. Now if the book's cover had been plain you never would have even noticed it and never would have read the back.
The reason I ask this question is because recently I've realized I absolutely HATE any book cover if the book has been made into a movie and now the cover of the book is the 'movie picture'. Example, The Road by Cormac Mcarthy. The book cover has the actor who plays the father in the movie on the cover and I couldn't stand it. Same goes for my book "Into the Wild". The book's cover was the movie poster. In fact I hated these two book covers so much I went down to Borders and exchanged them for the same books but with non-movie covers. Now I am happy and I plan on doing the same for my books, No Country for Old Men, Fear and Loathing in Las Vegas, and Call of the Wild.
Now going back to book covers in general, I think I'd rather have a book with a plain cover and just the title, rather than an ugly picture on the cover. For example, I recently saw a few different book covers for On The Road. I believe it is Penguin that puts out a book cover with a corny picture of a guy (probably Sal Paradise) hitchhiking on the road. The picture is so goofy and corny that if that was in my library I'd throw it away. Instead I'd rather the other book cover that was plain black with the title On The Road in big letters.
So to sum up, I strongly feel that a book's cover is important to the overall enjoyment of the book itself. When you close the book at night and stare down at the cover don't you want to stare down at a picture you feel is a good one?