WallstreetJournal:Did AT&T get a sour apple when it snagged the iPhone? Maybe. AT&T's exclusive right to offer Apple's smart phone over the past two years has attracted new customers, and at least initially enhanced the phone company's image. But it is difficult to know whether those benefits are worth what have been some considerable costs, both short and long term.

For investors, and for federal regulators investigating such exclusivity deals, it is worth considering some factors. While AT&T has disclosed at least 10 million activations of iPhones since it became available in mid-2007, only about 40% of those were new customers. That number dropped to 35% in the most recent quarter when the 3GS phone became available.

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