Have you looked to see what # of page you are on when you browse by category on Amazon. If you're buried deep in the search then not many people will even see your book. I never sold on Amazon but I've sold on other sites and coming up high in the search engine is very important to making sales.
No, but the each book has a section ranking each book by category. For example, it could be #395742 in "dark fantasy" right now. As for marketing, I've been relying on promotional art for DeviantArt, Reddit, FB, Twitter and Behance. Of course, only four characters have made it to the public eye so far. I'm gonna spend today and tomorrow making another poster for it, notably including the guy you see on my avatar.