Let's concentrate on the facts
The facts are these:- Spotify's ads make virtually no money and a pitfully small proportion take up the Premium Service.
In many ways Spotify is worse that Pirate Bay in that it PRETENDS to create revenue for artists and so lulls users into a false sense that they are participating in a brave new monetising model.
This is a LIE!
Spotify is a great user experience but as a monetising model it is a dangerous con.