Of those, YouTube has the lowest barrier to entry for users. I'd guess because of that low barrier to entry that YouTube serves the most music traffic, but I do

Of those, YouTube has the lowest barrier to entry for users. I'd guess because of that low barrier to entry that YouTube serves the most music traffic, but I don't have any stats to back up that guess. YouTube is such a popular resource for music that someone has taken to making a Chrome extension based around playing music from YouTube. https://streamus.com/ https://streamus.com/ The creator mentioned when talking about the motivation behind this project that they've had issues with the gaps in the subscription based services (Spotify, Google Music, etc), whereas they've had good luck with finding music on YouTube. If I were a musician in this situation I'd definitely not want to pull my music from YouTube.