I should start by saying I am a huge fan of spotify, been a paid subscriber since close to the beginning of availability in the U.S., etc. But today I went to the Song Radio playlist for Help by the Beatles and found a link in the header I hadn't noticed before: "About recommendations and the impact of promotion" - clicking it shows this disclaimer:

"In some cases, commercial considerations may influence our recommendations. For example, Spotify offers a promotional tool that enables artists and record labels to highlight priority songs, increasing the likelihood of them being recommended in specific algorithmic playlists: Radio, Autoplay and certain Mixes. This can help artists be discovered by new listeners and grow their fan bases, including prior to a new release, as part of a cultural moment, or in celebration of a milestone. For streams of those priority songs generated in impacted playlists, Spotify charges a commission. This tool is not active in other playlists, such as editorial ones."

What?

I'm disappointed but I suppose this is the endgame of any service: to squeeze every last nickel out of every corner of the application. And in this case they took the term "Radio" literally and realized there was payola money to be made (which is legal with disclosure).