When thinking about the cost of providing the services journals provide, I’m always struck by the example of PloS - non-profit, set up with the mission of promoting open access, and just about surviving by charging authors $2000-$3000 per article. I can only conclude that managing journals is not as cost free as most people in this thread seem to think, for whatever reason.
I mean referees don't get paid. And there's nothing else to do really if it's a digital journal.