@Lucas: Couldn’t some of that deficit be offset by in-page ads? One of the big differences between old-fashioned radio and web-based music distribution is that, in addition to listening to a flow of music that can be interrupted by ads, users also visit web pages on which visual ads can be placed. This is another area where streaming seems a big disadvantage to me over real mp3s with solid URLs aggregated in sensible ways. If each page or playlist (i.e. album/artist/mixtape) has a corresponding page where listening begins and additional metadata and fan activity resides, then there’s a second monetization opportunity to which all the standard tools of web advertising can be brought to bear. Streaming has always seemed like a weak technology mostly used to try to artificially keep the use case/business model as close to terrestrial radio as possible. While the progressive download of mp3s theoretically lets users take the songs offline where they can listen without exposure to ads, they also are the key to improving user experience online to an extent that could make it possible to reach web scale audiences. And the real secret is that most users don’t want to download most mp3s anyway. Actual files fill up your hard drive, they partition your library across individual machines, etc. The only unique virtue of actual mp3s is that they can make it onto iPods and streams can’t compete with that anyway. Plus, as portable devices become increasingly connected (cough, iPhone, cough) that issue will become less and less important. If all the music had solid mp3 urls, downloading would fade away, not because it would enable successful enforcement, but because it would simply be less convenient than progressive download in the browser.