According to Billboard in a story titled “Spotify Officially Hits 50 Million Paid Subscribers“, the “official” announcement came from a tweet:
https://twitter.com/Spotify/status/837404762895233024?ref_src=twsrc%5Etfw
Spotify has a family tier at $14.99 in the US for up to six “family” members. Does the “official” subscriber number count a a family subscription as one subscriber, six, or the actual number of family members that sign up?
We don’t know the answer, but we do know that TechCrunch, CNET, Newsweek and other people who should know better all dutifully reported that Spotify now has 50 million “paying” subscribers. Reuters reported the same story with a more subdued headline: “Spotify Says It Reached 50 Million Subscribers“ (possibly due to these people called “editors”). A little more factual, a little less Kool Aid. Ubergizmo is in between with “Spotify Is Now Boasting 50 Million Paid Subscribers”—almost right, there was a boast, just not about “paid”.