Critics are taking issue with the claim that Amazon Music Unlimited is growing faster than Spotify. Music Business Worldwide has determined that Amazon grew more percentage-wise (70 percent year-over-year versus Spotify's 32 percent), but it was well behind in terms of raw subscriber numbers. Spotify hit the 100 million subscriber mark by adding 25 million Premium members between its March 2018 and March 2019 quarters -- that's just about double the 13 million Amazon added over a similar period. That rate held up in the second quarter, where Spotify's 108 million total subs represented another jump of 25 million.
Amazon's growth is still noteworthy. Outside of Apple Music, it's hard to find any other streaming music services burgeoning at rates even vaguely comparable to Spotify. And that 70 percent relative growth is nothing to sneeze at -- it shows that Amazon Music is evolving from a convenient service for Echo speaker owners into something more broadly appealing. Unless Amazon can keep growing at a heady pace, though, a top dog like Spotify is unlikely to feel seriously threatened.