iPhone 3G AT&T Windfall

Becoming the exclusive carrier for the iPhone (in the U.S.) appears to be the smartest move AT&T could have made so far this century.

According to the recently released results of a study by the NPD Group, a research market firm, 30 percent of buyers of the iPhone 3G this summer had to switch to AT&T from a different carrier.

Aligning themselves with the iPhone, currently the top selling smartphone in the country, appears to be a bigger boon to AT&T’s customer base than any other business move they could have made.

Where did most of these “defectors” come from? (Or, to put it another way, which carriers are people dumping to move to the AT&T iPhone 3G?) Verizon Wireless, mostly, with nearly half of AT&T’s new iPhone 3G customers switching from there. Another quarter came from T-Mobile, with another 19% coming from Sprint.

In the June-August, 2008 period, the iPhone increased its smartphone market share by half.