Google Play Music has been steadily improving its services in the recent past in order to compete with other popular streaming platforms like Spotify. The latest installment has seen it increase the capacity of its free locker service from 20,000 to 50,000 total songs.
This means that you can store 50,000 of your own songs on Google's cloud storage and listen in to these tracks from any device that you may have connected to the service. Spotify has some kind of local file support, but nothing as large or in-depth as Google's offering.
After taking over the playlist company Songza in 2014, Google allowed users access to a song suggestion feature alongside letting subscribed members play YouTube content in the background on their mobile devices.
I'm a currently Spotify member - would I make the switch? I'll certainly look into it now.