Heh, I don't even doubt the legality, I was talking purely about subjective expectations, about how it feels to us.

On top of that this data can be completely anonymised without compromising the data. All you need is an entry "a user listened to a song".

This probably gets more hairy when it comes to a user's listening history and things like Spotify Wrapped, discover weekly etc., but this is one of those areas that fall under expectations from a service, legitimate interest etc.

I think this discussion was about switching a pooled model to one where a user's subscription payment is directly split according to that user's listens. That requires unaggregated and unanonymized listen data.

Ah true.

This is solved (well, not solved, but handled) by not having a direct link between usage data and the user. So you store your data as <usage, proxy_id> which references <proxy_id, user_id> which references <user_id, user PII>. This way you can always easily break the connection to PII (if the user requests deletion) while keeping per user data.

But true, it's not anonymized in this case.

Even though they just need a total plays sum to pay out to artists, Spotify for sure stores every play by person. You can request your data from them and see for yourself - it's of course necessary for their recommendation services, and even just providing the listening history back to you is a service many people want badly (it is the whole point of services like last.fm!)