The latest study from research firm MusicWatch is likely to fuel the arguments about the “value gap” between free, ad-supported music streams and the revenues they generate for rightsholders. The study quantifies weekly music listening in the US, claiming that Pandora’s free tier accounts for 27% of it, with YouTube also accounting for 27%, and Spotify’s free tier 11%. That means 65% of American music-streaming comes from those three ad-supported services alone, compared to 7% from Spotify Premium, 3% from Pandora One and 2% from Apple Music on the premium side. As the RIAA revealed yesterday, when it comes to actual revenues, subscription services accounted for 62.9% of US streaming revenues in the first half of this year, while ad-supported on-demand plus SoundExchange distributions accounted for 37.1%. As MusicWatch points out, though, one of the most interesting questions in 2017 will be how much of that free Pandora listening can migrate to the company’s new subscription tiers.