Hi,
I think it all depends on how much time, effort, and money you're willing to put into promoting your book. Amazon can sell books, but only if someone knows about it and is looking for it. If you're going to do an effective job of promoting your book, you will outsell Amazon, unless you get on the best-seller lists, and if you do that, you really don't need Amazon. The best kind of promoting is face-to-face, person-to-person, identifying specific markets and developing ways to reach them. For Black authors, Black book clubs are probably the most important sites to reach. Black librarians can also help. If you're able to identify book stores, Black book clubs, and you are willing and able to go to them, hold readings, signings, and get the word out about your book, you are likely to do well. Getting book reviews on sites where people can see them is also important. Big publishers send their authors on the road, because that is the best way to reach people who will learn about the books and buy them. Localized interviews are important - radio, television - anyway you can expose people to your book. I don't think there's any silver bullet. If there were, we'd all be selling so many books that we'd run out of paper to print them on. In many ways the art of selling Black books is terra incognita, the unknown. We're all trying to discover it, and if we can share information and support each other, we may find ways to do just that.