There is actually cross-over, whether you like it or not (most people don't). Youtube Music Key: https://www.youtube.com/musickey
http://lifehacker.com/whats-the-point-of-youtube-music-key-1...
I say YouTube is probably the number one way most teenagers actually listen to music. This isn't music videos mostly. It is pictures of the cover art and the music. I seriously listen to my music through YouTube in another and I am rarely disappointed in not finding the music I am looking for.
What is not to like. I can listen with the screen turned off. I use this feature to listen to one off podcast I would like to list to and the YouTube play list made by users are amazing. Also to have no ads while listening to YouTube music is great.
No ads is nice, but useless for anyone who is willing/able to install an ad blocker on their phone. You can promote content producers more effectively by spending the money you would drop on a subscription on buying an album, going to a show, subscribing on Twitch or becoming a patron on Gratipay anyway.
Offline access is nice, but other commentors claim it's "clunky", and if it's not especially convenient, then it doesn't give me anything I havent been able to do for the last decade with youtube downloader apps.
So really all it does is make the mobile background play a paid feature, which is obnoxious.
It's very anti-user, I use it to listen to longer podcasts in the background.
Worth rooting for: http://repo.xposed.info/module/com.pyler.youtubebackgroundpl...
http://kaeruct.github.io/posts/how-to-use-the-youtube-js-api...
If I want to watch music videos I'll go to the Youtube app. So damn annoying when I accidently tap the play video hover button when I really meant to swipe to the next song.
If it weren't for YouTube's popularity I'd say the integration was a sign of desperation.