Why do you stalk me book cover? It's not intriguing. The eyes don't even have a context in most cases. These aren't even spy dramas they're supernatural romance or teen contemporary. Apparently love is now stalking and general creepiness. I wouldn't mind so much if it were actually relevant to the story or mood - I just think it's people getting lazy with their marketing. Remember that one cover that had the one eye everyone loved? Yeah me neither. So why copy it on virtually every book cover these days?
OK, so it worked for the Host. Yes I read it because I refused to read Twilight and wanted to know if Stephenie Meyer (dumb spelling) was as awful as I thought she would be. I have to admit the setup was great but lacked any real emotional depth. It started out with a kind of Halting State by Charles Stross idea and flat-lined. My point is that the glowing eye on the cover was actually part of the story and not just a cheap attempt at being mysterious.
My humble irrelevant opinion is to please stop doing this to your audience. Intriguing and mysterious isn't the same as open-mouth breathing and stalking glares.