In media res

I just finished a long novel so I've been catching up on my short story reading. And wow, these shorts are all starting with a bang. In fancy literary jargon we call this in media res, which is Latin for "into the middle of things." I'd go so far as to say, all the first lines are bang! pow! dramatic. I'd heard literary conventions were shifting to take into account our decreasing attention span and these stories definitely bear that out. So, artists of the short story: take note.

An interesting related issue is: how soon in a novel does the author have to hit the reader over the head with excitement? Should it be the first line? The first paragraph? Or do we have at least until the end of the first chapter? Of course, this does vary by genre. (Literary novels never have to have anything exciting happen. :) Ha. I kid the literary authors.) A few years ago, I would have said we had until the end of the first chapter. But now, with the increased pressure to sell books I'm thinking a bang! pow! novel first line is not a bad idea.

What do you think?