20% of sales of songs from Pandora come from the iPhone App

"Users are buying about a million songs a month now from these affiliate links on Pandora, CTO Tom Conrad tells me. Of those, a solid 20% are coming directly from Pandora’s iPhone app, which includes an easy link to open the iPhone’s iTunes app, and buy a track."
Source: Pandora CTO Tom Conrad, in Techcrunch, 7th May 2009