You Can't Judge a Book By It's Cover...

Actually I disagree with that statement. Here a just a few of the things you can tell about a book just by looking at the cover.

Old School Books:
1. How freaking long it is. Let's be honest any book that is over 1500 pages...is going to be high-faluting and a HUGE commitment.
2. How good it is. If the book is worn and clearly overly read then the odds are that the book is going to be totally awesome. If the book is not well read and is, you know, covered in stains and muck, well why would you waste your time.

Modern Era Books:
1. Everything about the book. I mean seriously the books now have pictures that are basically a snapshot of what the book will be. If the book is frilly and cute...the book will be frilly and cute. If the book has a steamy lover on the cover the book will be steamy and highly inappropriate. If the book cover looks like an actual photograph of someone or a cartoon of someone then the story is more about people and their relationships. If the cover is more abstract or text based then the book is going to be pretentious and think it's all about the words.
2. Titles. Honestly a title is basically the whole book. A summary of the style and the form the book is going to take.

Another thing the phrase goes...you can't judge a book by its cover, but you cant tell how much it's going to cost.