According to Triton Digital, which tracks Web traffic, Pandora, which streams a full spectrum of music 24 hours a day, generates the biggest numbers. (NPR.org, the network's overall website, ranks sixth, with NPR Music accounting for 15% of its audience.) Sites like Pitchfork, which appeals largely to indie-rock fans who appreciate not just music and videos but at-times-scalding reviews, are also playing the game.
WSJ: The Improbable Rise of NPR Music