I'm reading through M. Louisa Locke's blog, and she points out something that not only had I given literally no thought to, but that it hadn't even occurred to me to give any thought to: Increasing your book's exposure on Amazon by getting into a less-populated category.
I list Trang as "adventure science fiction," and of the nearly 14,000 Kindle science-fiction books listed on Amazon, almost 7,000 are adventure science fiction. Oh. The only other genre sub-category is "high tech science fiction." I may be doubting that Trang is really adventure science fiction, but I know for damned sure it isn't high tech. (And yes, it is absurd to have only two sub-categories--by these standards, the works of Philip K. Dick are adventure sci-fi.)
The other two science fiction sub-categories are more about how the books are packaged: "anthologies" and "series." Series! Trang is part of a series, and there are only 150 books in that sub-category. So, I think once Trust is in the bag, I will get both books on that list, too.
ETA: She also has a great series of posts on how to edit your own work that begins here.