Back in October 2015, Apple CEO Tim Cook announced at the WSJD conference that the company's streaming music service, Apple Music, had 6.5 million subscribers. Now, it's been revealed that Apple Music has just reached 10 million paid subscribers, representing a 50 percent increase in users in only three months, according to the Financial Times.

When Apple music launched in over 100 countries in June last year, it offered free three-month trials to users. Anyone who didn't cancel the service before this period ran out would become paid subscribers. There were several reported design and technical issues with Apple Music when it launched, but this didn't stop just under half of the 15 million people who signed up for the free trial sticking around after it became paid-for only.

Subscriber numbers have jumped since October, making Apple Music the second largest streaming music service behind Spotify, which last announced it had reached 20 million subscribers and 75 million active users three weeks before Apple's service launched. Spotify's numbers will no doubt have swelled since then; the Swedish company's head of PR, Jonathan Prince, told The Verge that the last half of 2015 was "the fastest subscriber growth in Spotify history."

Music industry analyst Mark Mulligan predicted last month that Apple Music would reach 20 million total users by the end of this year, and could top Spotify in 2017. Apple does have the advantage of boasting exclusive access to music from a number of artists, the biggest being Taylor Swift.

Both Spotify and Apple Music cost $9.99 a month. But for iOS users who subscribe to Spotify through iTunes it's $12.99 a month as this covers Apple's cut of App Store proceeds.