1.7 kindles per subscriber per year, you mean. It's probably cleaner to work out how long it would take to recoup that 'investment' assuming subscriber readership & ad revenue don't change. He also assumes wages outside the newsroom are all in printing, which makes no sense.
The article says 2 kindles over a year's costs, so his t=0.5 yr. If cutting out 4/5 of the dead tree edition doesn't do much outside raw materials, t=6yrs, which is crazy.
Thing is it's all irrelevant. The assumptions & lack of information make the calculations useless. We already knew t>0, that's not a surprise.
The article says 2 kindles over a year's costs, so his t=0.5 yr. If cutting out 4/5 of the dead tree edition doesn't do much outside raw materials, t=6yrs, which is crazy.
Thing is it's all irrelevant. The assumptions & lack of information make the calculations useless. We already knew t>0, that's not a surprise.