Prepay doesn't seem like something that would drive a market difference in the US. The carrier prepay options are much more limited here. Similarly, I wonder h

Prepay doesn't seem like something that would drive a market difference in the US. The carrier prepay options are much more limited here. Similarly, I wonder how the the age or creator of the mobile infrastructure (7 & 8) figures into offering of mobile devices independent of network access by carriers - maybe in the homogeneity of the mobile network?