Judge a Book by its Cover?

When I am getting ready to read a book, I rarely simply pick up a book that I have no previous knowledge and start reading. I would never walk into a library, pick up a book and decide to read it based on a cursory look at the cover, back cover, etc. I only read a book if I have read one by the author previously, if I'm forced to read it by my English teacher, or if the book comes with the recommendation of someone who has similar interests in books as me. Books rarely capture my attention and maintain it throughout, but the few exceptions are usually thrillers or suspense novels. The Da Vinci Code and Angels and Demons both by Dan Brown. I think they were able to hold my attention because they had a fast pace with a particular emphasis on suspense and action.