Now we know why Apple (AAPL 0.52%) is taking on Pandora (P) with iTunes Radio.

Nielsen Soundscan and Nielsen BDS came out with music consumption trends for the first half of 2013, and it's not very flattering for the traditional iTunes model. Streaming usage is up 24% at a time when individual track downloads fell 2%.

In this video, Fool contributor Rick Munarriz explains why Apple and even Sirius XM Radio (SIRI -4.43%) have shifted from emphasizing download revenue to keying on streaming as an incremental revenue source.