Cnet: Amazon Wireless, Amazon's cell phone and wireless store, has announced a $15 Digital Bonus offer for customers who buy new Android phones from July 11 until October 11, 2011. The $15 credit will be in the form of $5 credits each for the Amazon Appstore for Android, the Amazon MP3 store, and the Kindle Store. You'll have until November 12, 2011, to use them, after which they'll expire.