It is not free with Prime, just $2 cheaper ($8 vs $10/mo).
I think what is driving Amazon Music subscriptions is the proliferation of Echo devices. It is easy to auto-subscribe from the speaker itself (sometimes too easy, to the point of being accidental), e.g. when you ask it to play a song.
There's a free tier Amazon Music of 2 million songs included with Prime membership. That's the free music streaming my friend was using for 5+ years. She then upgraded to Amazon Music Unlimited for extra $80/year.
Can't tell if the article's 13% for Amazon Music is counting the free tier users.
Nah, I'm a Prime subscriber and get the occasional email from Amazon that i have an unused advantage from my subscription and should enable Amazon Music.
I think what is driving Amazon Music subscriptions is the proliferation of Echo devices. It is easy to auto-subscribe from the speaker itself (sometimes too easy, to the point of being accidental), e.g. when you ask it to play a song.