"You can't judge a book by its cover."
Really? Really? I disagree. While there are some good books out there with poor covers (due to a variety or reasons, such as poor art decisions, financial limitations, and just plain bad judgement), you will and should always initially judge a book by its cover.
The cover of a book is the one-shot initial impression of the book. It should reveal several things. First, it shows how much faith and the level of effort that the author or publisher has placed into the book. Are they proud of the book and have they placed as much effort as possible into the creation of the book (including the cover)? Secondly, the book cover should attract you to give it a chance, to pick it up. Whether it is the feeling the cover embodies or the story or concept the design implies, the cover should reveal just enough emotion, genre, or story to pull the casual browser close enough to at least pick it up and give it a look.
I've been a huge fan of cover designs for a long time. I hope you find mine to be at least enough to give the book a chance.