Spotify seems designed to over-reward the high volume artists at the expense of the little guy assuming I understand their model correctly.
Current:
totalMoney x (totalListenTimeForArtist/totalListenTime)
imo the sensible system looks like:
PerUserMoney x (PerUserListenTimeForArtist/TotalUserListenTime)
ie distribute each users subscription (minus fees)
across the artists they list to so they don't just get dominated by big/popular music on repeat