Honestly I'm not surprized, and I agree with the ArsTechnica author:
Rogstad's dismissal of the findings don't take into account that the online music model has dramatically changed how consumers buy music. Instead of selling a huge volume of full albums�the physical media model�the record labels are now selling a huge volume of individual, cherry-picked tracks. It's no secret that the old album format is in dire straits thanks to online music, which is a large part of why overall music revenue is going down.
But the bottom line is, how can you argue with the numbers? I agree that yes, these downloads are illegal. But what these studies are saying is that the whole fight against it is pretty silly, even from the financial perspective, which is the only one that should even matter to a money-making entity.