Peter Krasilovsky and Jay Small have some thoughts about local online revenue growth and the inflection point at which a web operation outsells the print operation.
I've run those numbers, too, guessimating the future. It's total nonsense, of course; you cannot predict the future by extrapolating from the past because there are too many variables, you don't have enough data, and your model is doomed to be pathetically naive. But it's great discussion fodder to be able to say "Look, here in 2012, 2013, 2014, whatever, everything changes. What does it mean? What do we have to do to be ready?"
Several years ago economist Robert Picard drew this graph, which was used in a World Association of Newspapers strategy report:
... omitting any numbers and forcing us all to guess. Rosenthal Alves tells me Picard has updated his graph with some animations but still, sadly, no dates.