We all know the iPhone 3G is a popular device. But we just learned yesterday that one third of its users actually switched carriers to use it.  

According to a report put out by the NPD Group, Apple lured over many customers from different carriers, and encouraged many to join AT&T just to use their smartphone. Apple also made up 17% of the smartphone market for August. This is an 11% increase prior to the launch of the iPhone 3G.

Another interesting tidbit is that the overall cost of smartphones has dropped significantly to an average of $174 since this time last year. Fortune is also now reporting that Apple has reached their goal of selling 10 million iPhones in the past year based on ID numbers from individual iPhones.

[via mocoNews]