Epic Games has filed a preliminary injunction to stop Google from removing Bandcamp from the Android Google Store after the company threatened to do so. The reason? Because Bandcamp uses its own pricing system instead of paying Google an app store fee.

Bandcamp has its own in-app billing system, not Google's. As of 2015, the app didn't use Google's method because the company's policy didn't include Bandcamp's core business - digital music.
Bandcamp co-founder and CEO Ethan Diamond explained Google's threat in a post, adding that "Google is now amending its rules to require Bandcamp (and other similar apps) to exclusively use Google Play Billing for payments for digital goods and services, and of course pay a share of the revenue to Google."
Google's new policy update requires Bandcamp to switch its billing system to Google's by June 1, forcing the app 's CEO to choose between passing on fees to customers , passing on fees to artists, operating its Android business at a loss, or disabling sales on the Android app.

In its filing, Epic argued that changing the billing system would prevent the app from giving artists 82 percent of their revenue , because 10 percent would have to go to Google. According to Epic, “Paying Google even a 10 percent revenue share would force Epic to change Bandcamp’s current business model or operate the Bandcamp business at a long-term loss.” In addition, the change would prevent artists from receiving prompt payments that would take 15 to 45 days instead of 24 to 48 hours after a sale.
Switching the app to Google's billing system would require a complete rebuild of the Bandcamp app infrastructure, which would be time-consuming and labor-intensive. The music app is currently fully integrated with PayPal, but the announcement of the policy changes came a year ago, before Epic bought Bandcamp.
Source of information: tribune.com.pk
