AT&T had 100% of the U.S. iPhone market share (not counting the stray jailbroken and unlocked units on T-Mobile) until last month. The speculation for years preceding Verizon’s iPhone availability had been one of mass defection from AT&T to Verizon. Based on the information from Chitika (an analytics firm) as reported by MacRumors.com, this was not the case.
Initial reports of Verizon’s 12% marketshare just one one month after it began selling the iPhone is very impressive. However, as MacRumor noted Chitika’s metrics seems highly variable with recent updates placing the percentage at around 10%. Moreover, a water cooler sampling indicates that most Verizon iPhone purchases were not defecting from AT&T. This is good news for Apple since it means overall iPhone sales growth instead of a zero-sum game between AT&T and Verizon.