Ten years ago, the ebook market was just seeing the dawn of a new era. It's when I started to write novels and I geared toward the digital industry. So did the photostock market for book covers.
In the romance industry everything is about the couple on the cover. There's a high demand for photos of naked or nearly naked men and women. The sexier the pose the better, of course it's romance and one of the hottest markets is the erotic lines.
To boast sales, aim for them. Check out their sites and drop them an email telling them where they can find your work. It's a niche market, but one well worth exploring.
This photo begs me to give him a story.