“Will iHeart’s audience pay? You bet, maybe!” claims the slightly confusing headline for research firm MusicWatch’s latest blog post. In fact, the company has concluded that millions of iHeartRadio listeners *will* be prepared to upgrade to the company’s new $4.99 iHeartRadio Plus subscription tier. Its calculations are based on a survey of 7,800 American internet users, which found that a quarter of free music streamers in the US listened to iHeartRadio in the last month: nearly 40 million people. “That’s almost the audience level that Spotify Free obtains, and better than Google Play Music, Vevo or SoundCloud,” claimed MusicWatch’s Russ Crupnick. His survey found that more than 40% of those listeners expressed interest in paying for a Plus-like service, which if only half of them follow though and actually pay – with the caveat of there being typically two users per account – that could mean four million subscribers. “Considering the entire US paid on-demand universe is around 20m, that’s a solid chunk of growth in the paid sector ,” wrote Crupnick – although if we’re talking about iHeartRadio Plus, it’s strange that direct rival Pandora One (now also rebranded as Plus) isn’t included in the 20m figure.