How different is the iPhone 3G revenue model?

http://www.visionmobile.com/blog/2008/05/how-different-is-the-iphone-3g-revenue-model/

Addressable market (1Q 2008): 153 million users
Market penetration: 3-5%
Shipped iPhones (1H 2008): 4.02 million
Revenue per iPhone sold: $153
iPhone Published revenues (1H 2008): $619m

Addressable market (2Q 2008): 575 million users
Market penetration: 3-5%
Expected shipments (2H 2008-1H 2009): 23 million
Revenue per iPhone 3G sold: $50
Estimated iPhone 3G revenues (2H 2008 - 1H 2009): $1.15bn