I don't know how good Spotify plays are as an indicator of someone's popularity. I mean Weeknd's been in my top 5 Spotify artists for like the past 3 years. I'm not some super Weeknd fan though. I simply like his music enough to listen to from time to time but not enough to actually buy any of it. I suspect that a lot of the people who get an unexpectedly high number of Spotify plays result from that.
On a completely different note, Spotify is pretty damn good at putting together mixes of songs similar to what you were listening to. What I mean by that is that if you play an album or playlist, Spotify will continue playing music that should be close to what you were listening to. It does a good job of matching things up. It usually has me listening to artists I've never even heard of.
