Kindle-owning bibliophiles are furtive beasts. Their shelves still boast classics and Booker winners. But inside that plastic case, other things lurk. Sci-fi and self-help. Even paranormal romance, where vampires seduce virgins and elves bonk trolls.

The ebook world is driven by so-called genre fiction, categories such as horror or romance. It's not future classics that push digital sales, but more downmarket fare. No cliche is left unturned, no adjective underplayed. At the time of writing, the bestselling Amazon Kindle book was Asylum Harbor, by Traci Hohenstein. Crime sells. Try a sample, I dare you. In digital, dross rises. But does this have implications for publishers' decision-making, as we increasingly migrate?