Judging books by their covers

I was perusing the bookshelves of Target the other night and wandered past the "Young Adult" section. "Did the lights go out?" I ask myself. No, it's just that pretty much every book for teens and "young adults" are black. I know they're into vampires big time, and you can't really have a happy, cheerful color on the covers of books about vampires -- but not all those books are about vampires.

The content of the book doesn't matter if the cover doesn't appeal to the target audience. Obviously book publishers have discovered young adults have an affinity for black.

Regardless of what "content" is in your "book" (the product you sell, if you're not getting the metaphor), is your cover designed to reach your target audience?

Now if I were publishing a popular book for young adults, and knowing that everyone else's book would hardly be distinguishable from each other, I'd make mine in red.