The biggest reason to upgrade if you use Spotify’s mobile app on your phone is the ability to play any song you want. With the free version, you’re forced to listen in shuffle mode on your phone outside of 15 on-demand playlists. With Spotify Premium on your phone, you can, for example, end an evening with Poison’s Every Rose Has Its Thorn and Motley Crue’s Home Sweet Home without power ballads from Warrant, Whitesnake and Cinderella ruining the moment.