$18 For Every iPhone

I had always been puzzled by the new found joined-at-the-hip friendship between Apple and AT&T when the iPhone was released, until recently.

It turns out that AT&T is paying Apple $18 each month for every iPhone user on the AT&T network for the exclusive relationship. This estimate, from Piper Jaffray analyst Gene Munster, sheds some light on the strict attitude Apple has taken with people un-locking their iPhones to work on carriers other than AT&T.