Back in March, writing about the IFPI's response to the EU study finding that unlicenced filesharing might lead to a small rise in sales, I asked if it could possibly be true that Nielsen counted plugging in an iPhone to recharge as a visit to iTunes.
The IFPI were polite, but fundamentally unhelpful when I asked them about what they were basing this claim on; happily, Nielsen were a bit more forthcoming and confirmed that iTunes data does include plugging in the phone:
After some internal research, I can confirm that IFPI's description of the NetView methodology is correct. How Nielsen looks at iTunes: anytime the app is active in focus, which can include any iTunes activity from listening to music to purchasing movies to synchronizing devices etc, which would include purchasing music but not limited to this activity.Blimey.
I don't think this is quite the game over for the EU study that the IFPI thinks it is, although it weakens the strength of the research. The study had expressly ignored Amazon data because it was impossible to tell 'purchasing music' from the other activities one could do on the site; it might have been wise to exclude iTunes for the same reason.
However, the survey did find similar results for other services - it wasn't relying solely on iTunes data - so while it's not quite so solid as it appeared at first, it's still valuable if approached with caution.