There is an interesting thread at the KindleBoards about what makes your book unique. Here is what I wrote:
In my case, in the fantasy genre, I try to write what piques my interest at bookstores or at online ones.
In a nutshell, for my fantasies, it's male main character(s). The significant relationships are usually one of the following: bromance or buddy-fic, family-pairing, or loner against a male antagonist. This usually means little to no undercurrent of romantic relationships for the main characters. Finally, I need weird settings, plot, and/or magic. Sometimes the weirdness is in the background, but it still affects the rest of the novel. Also, many times I borrow from real cultures or time periods for ideas or framework.
17 minutes ago