Apple CEO Tim Cook has given an update on the adoption of Apple Music, the company's streaming music service — it has over 15 million users right now, with 6.5 million of those paying $9.99 a month and 8.5 million still on the three-month free trial. That makes it a smaller but significant competitor to Spotify which, last we heard in June, has 20 million paying customers.

Apple Music went live at the end of June, so October is the first full month that Apple has started collecting payments. It's more than possible that a lot of people forgot to cancel their subscriptions and were charged for October, though, which might have skewed the figures. And people are still starting to use it for the first time — in August, Apple's Eddy Cue said that the service had 11 million trial subscribers, meaning it's grown by 4 million non-paying users since.

It'll take a while to assess the popularity of the oft-maligned service, then, but Cook himself seemed pleased enough with its progress tonight. "It's going really well," he told Wall Street Journal editor-in-chief Gerard Baker on stage at WSJD Live. "Fortunately, lots of people are liking it."