Genre hopping as a writer, I was told when I got into the biz, is like visiting foreign countries. You have to shift gears when you cross the borders, speak the language fluently, understand the native philosophy, humor and customs, and try not to piss off their police. What one does in the U.S. of Romance one does not do in the People's Republic of SF.
As a rookie I thought this was remarkably stupid. Like the Berlin Wall was. I still do, but I've slammed into enough genre fortifications that I've developed unwilling respect for how thick and immovable the isolationism that built them is.
Every time a book appeals to readers of more than one genre, it kicks a hole in the wall and expands a readership. Sometimes this is deliberate on the part of the author, but generally it's the readers who smuggle the book across the borders. I think the reason for it is simple: the majority of readers may have a favorite genre but are not exclusive to it. People who love books will read anything and everything. I know, I'm that type of reader.
Among the many challenges writers face, shrinking readership is one of the toughest. Genre walls aren't helping; they're adding to the problem. We have viral marketing; what we need now are viral novels.
I some ideas on the writing side, which I'll get into next week, but what element(s) in a story, if any, do you all as readers think makes a novel jump over those genre walls?