Amazon does the same thing. Although their "free" storage tier is a bit anemic, and they want an extra couple bucks a month for a generous tier (since they're a couple bucks cheaper with a Prime membership, that would basically take you back to square one). However, their differentiator is that everybody gets unlimited storage for content purchased from Amazon.

I keep hearing about how nimble and agile Spotify is, and how their tech stack and team structure lets them add features quickly. I wonder why they haven't offered upload storage yet, and whether that's coming?