As part of a trial (which does not affect those not paying for Spotify Premium), music labels will be able to promote songs by putting them into users' playlists as sponsored content.
Those whose accounts are affected - and it's only a small number at the moment - are able to opt out by going through Spotify's settings.
If this proves a viable option for Spotify to realise some revenue from its non-paying users, it could channel that money into hi-res music or more exclusive songs as a way to stay ahead of Apple Music, Tidal and Amazon Music.
Since the company says that music services aren't paying artists enough, getting something out of its free users is certainly a priority.
More after the break