Tim Cook announced that Apple Music has more than 50m users, counting paid and trial subscribers. The company “appears”—Cook’s word—to have taken “the leadership position in North America” during the quarter that ended 6/30.

Whether Apple is in the lead is debatable. Spotify has never released stats breaking down user bases but the company Statista released a study this year that reported Spotify had 52m monthly active users in the U.S. Obviously, not all of those are paid and Spotify’s worldwide subscriber count has grown to 83m; it's not necessarily an apples to apples comparison.

In noting Apple Music grew more than 50% over the last year, Apple CEO Cook said there were limits to the growth.

“The key thing in music is not the competition between companies that are providing music,” Cook said on a call with investors and analysts. “It's the real challenge is to grow the market, because if you add everyone up that's providing subscription music today or streaming music, it's, outside of China, it's less than 200m probably around the world.

“And so it does seem to me there's an extraordinary opportunity in that business to grow the market well and I think if we put our emphasis there, which we're doing, that we will be a beneficiary of that as other people will as well. But I like where we are.”

The services unit that includes Apple Music and iTunes has generated all-time record quarterly revenue of $9.5b. Cook said the division is on target to reach the goal of doubling fiscal 2016 services revenue by 2020.