There's no set "pay per stream" in Spotify or the other streaming services. There are a lot of different factors that affect how much a stream in Spotify is worth in royalties.
How much each stream pays varies greatly depending on things such as:
Whether or not the Spotify user is Free or Premium (a Premium stream pays more than a Free stream)
Which region they're listening from (different regions have different payment in Spotify, since the Premium subscription fee varies between countries)
The time period when it's being streamed (payment also varies in Spotify from day to day, based on the total number of Premium users)
If the track is receiving unique streams (repeated streams from the same user will not be counted for royalties, see more info below)
So in summary, there’s no way to know exactly how much a stream is worth in royalties, since it varies depending on many different factors. Feel free to check out Loud & Clear by Spotify to learn more about royalties in relation to streaming.
A final note about abnormal streaming activity and how it relates to royalties:
When the same Spotify user streams the track multiple times, this is called abnormal streaming activity. Spotify has systems in place to check this and repeated streams from the same user will not be counted for royalties.
Abnormal streaming activity can be the result of one of these things:
Paid promotion through a third-party service. This usually means that the artist has paid to have their release(s) added to playlists with fake listeners. (Always make sure all playlists you pitch your music to are legit).
Systematically putting the song on repeat for a very long period of time.
Please don’t engage in abnormal streaming activity as this might lead to:
Stores not paying out your royalties
Amuse account getting frozen/ deactivated
Releases taken down, either by the stores or Amuse