US operators are enabling customers to pay for Android Market applications via their monthly mobile phone bill. Unstrung reports that, instead of paying for the apps with credit cards via Google Checkout accounts, T-Mobile has introduced ‘carrier billing’ for the Google-backed application store. The article adds that Verizon Wireless is working on introducing the service for its new Android devices (the Droid by Motorola and the Droid Eris by HTC), and Sprint is also reportedly working on carrier billing for its Android offerings.

The concept of carrier billing has had mixed reviews in the mobile industry. Unstrung notes that Nokia has previously stated that app sales jump by 70 percent when operators move from credit card billing to carrier billing. However, Apple’s App Store – the industry’s poster child for this booming market – has seen massive success (over 2 billion downloads) despite requiring users to own an iTunes account in order to purchase apps.