I will be brutally honest from the start of this post, nothing turns me off a book quicker than a half naked body. Once I see that I don't even bother about if the story has any worth, to me the cover said everything.
Other pet peeves include titles with a sexual meaning and of course anything related to zombies. In my opinion any book which stars off with a half naked body on the cover or a sexual undertone for a title is not (!) worth my time, as the plot is obviously "How many times per page?"
Zombies per se' turn me away by the sheer mass of people writing the stories on line and in print -- talk about pulp fiction -- and most of the stories have little or nothing to do with zombies from what I've seen. Zombies are not people with skin falling off, spreading plagues, they are real people brought back from a deep sleep by a bukor or a practitioner of the dark arts.
I admit, I might be missing something good but on the other hand... a dearth of books about a subject means you have a lot of copycats -- after E L James there were a lot too -- I will take my chances on things not related to mass publication ty, I am not averse to trying new writers, if I feel the story is worthy.