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Google admits Spotify pays no Play Store fees because of a secret deal | TechCrunch
(techcrunch.com)
This is a most excellent place for technology news and articles.
The thing is that any other competitor music app (or other app in general) faces the monetary barrier that Spotify secretly doesn't face in order to process subscription payments through Google Play is anticompetitive.
In this way, Google is also acting more like a market-maker than merely a competitive player or partner in a free market, where they can decide who the dominant music streamer could be.