US internet radio platform Pandora is reducing CD, MP3 listening and AM/FM radio music listening behaviors, according to research from the NPD Group. 

NPD says that, since 2009, the percentage of Pandora users who also listened to AM/FM radio declined by 10 percentage points, those listening to CDs on a non-computer device fell 21 percentage points, and listening to digital music files on portable music players also dropped 21 points.

Part of these declines can apparently be attributed to the ...