"There [does] not appear to be an upside," says Prosthetic co-owner E.J. Johantgen. The only income from the service comes in "fractions of pennies," even on their biggest titles, he goes on ... "I would like to see what their projected ad revenue would be. Then we could really determine if their rates are fair."
The article also points out that since the four major labels have an ownership stake in Spotify, they have access to revenue from both premium subscriptions and advertising; on the other hand, independent labels like Prosthetic only receive pay-per-stream royalties. Other indies such as Metal Blade and Century Media have pulled their catalogs from the service in recent weeks for similar reasons.