“You want to remember that while you're judging the book, the book is also judging you.”
“If you cannot judge a book by its cover, surely we should not judge an author by one book alone?”
“You CAN judge a book by it's cover!”
“You should always judge a book by its lovers.”
“You can't judge a book by it's cover but you can sure sell a bunch of books if you have a good one.”
“Of course you can judge a book by its cover; moreover, we are obliged to.”