It's rather simple. They take the amount that their profits were going up per year since before the whole p2p movement started, then assume it should have followed a curve like that forever (If not more because of the "we are awesome and deserve more" effect.
Since it hasn't, their "losses" have become the difference.
Slashdot Mirror
What about the hidden cost of more malware written for linux as adoption increases? Haha
It's rather simple. They take the amount that their profits were going up per year since before the whole p2p movement started, then assume it should have followed a curve like that forever (If not more because of the "we are awesome and deserve more" effect. Since it hasn't, their "losses" have become the difference.