Google forcing Android devs to use Google Wallet lest their apps be purged

http://www.reuters.com/article/2012/03/08/us-google-idUSBRE8271CJ20120308

Google warned several developers in recent months that if they continued to use other payment methods - such as PayPal, Zong and Boku - their apps would be removed from Android Market, now known as Google Play, according to developers, executives and investors in mobile gaming and payment sectors.