This guy had some fairly innovative designs, is reasonably affordable, and is also really helpful in making changes and working with the author to provide the desired cover. And we all know, people judge books by their covers. Exclusively.
But check this out:
He did three mockups and wrote a little article about it. I am a marketing genius.
Ok, so I lucked out, and he's really cool. Check out his work. He also writes great blog posts on design. Best of all, he understands branding, which is exactly what I need, as all of my books seem to be in different genres.
On the other hand, I got my ass handed to me here. But I'm fine with that.
"Why Is My Book Not Selling?" - These people will tell you exactly what they think. This sort of criticism is worth far more than the opinions of family and friends, commercially, but it's also a lot more useful than the tripe you usually hear in a one-star review or something. Imagine a school of professional piranha stripping your novel bare en masse. Then you take the skeleton and rebuild it.
It is an invaluable service. The cost? Free. But I hope you respond well to criticism...