Hugo wrote: So let's wait before we hail her as a phenomenon.
I disagree. You have to compare her to people that she is comparable with. Like Tinashe, Jhene Aiko etc...any type of alternate R&B female artist (who all have done mixtape prior to their debut album as well). And while Jhene has had some success, Tinashe has only had one song that was hot and album that sold triple pancake (love ha tho).
I think SZA's success, while yes isn't super ground shaking form an overall pop level, but I would consider it a phenomenal success compared to her competitors, and the market that she is...that doesn't buy music. They might buy hip hop albums (which yes, she has a hip hop backing label support), but R&B albums? When was the last huge R&B female album that wasn't Bey or Rih (who are technically pop stars now due to their catastrophic success)?
And honestly, We are in the streaming era. That counts now...no matter how any one feels. That a major way of how music is consumed. A lot of folks don't buy albums anymore...hell I don't. So I don't think it's fair to try and hold her actual album sales to her streaming counted sales against her.