The design on the cover

One of the most important selling tools for a book is the design on the cover. It is so important because it is the first part of a book you see. Say you were just skimming over the shelves in a library not in search of any particular book, the one your most likely to pick up would be the one that is most visually appealing to you. It is also important that the design has relevence to the story so that people can get a rough idea about what the story is about or at least what the genre is so that people don't pick up the book expecting it to be something that it's not. When I have no idea what i'm looking for in a library I tend to pick up books based on what their cover looks like. But for me, the design of a books cover usually isn't enough;  so I would have a look at the title and a read of the blurb before I would make the decision.