Spotify and Apple Music are facing increasingly tougher competition from Amazon when it comes to adding new paid subscribers to their services.

Amazon Music Unlimited was the fastest-growing music service over the last year according to new data that shows its subscriber base grew by 70%, even though it launched a year after Apple Music.

With more than 32 million subscribers, Amazon Music Unlimited is on pace to catch up to Apple Music’s subscriber numbers in the next year or two. Spotify has about 100 million subscribers but is only growing at about 25% per year.

“Amazon is the dark horse [in music],” Midia Research analyst Mark Mulligan told the Financial Times. “People don’t pay as much attention to it [as to Apple and Spotify], but it’s been hugely effective.”

One market that Amazon Music Unlimited is capitalizing on is older people. Nearly 14% of Amazon Music’s subscribers are 55 or older. Only 5% of Spotify’s users are in that category. Integration with Amazon’s Alexa speakers has also been a big boon for the service.

Pricing is another one of Amazon Music’s big weapons. The service only costs $7.99 per month if you’re a Prime subscriber. The company is also offering a deal right now that lets you try Amazon Music Unlimited for 4 months for just $0.99. The offer is only available for a limited time though so take advantage while you still can.