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 fo

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!)