In a note to clients — as reported by “Fortune” ( — Piper Jaffray analyst Gene Munster says Apple made two big mistakes when it launched the iPhone.

Mistake one: Apple didn’t originally subsidize the iPhone, but it quickly corrected this error by offering the original iPhone at a lower price shortly after its release, and offering the iPhone 3G at a subsidized price one year after the original iPhone launched
° Mistake two, per Munster: Apple’s exclusive agreement with AT&T has limited demand for the device.

“We expect Apple to correct this issue by the end of [the first half of 2011] and add Verizon to the list of carriers that sell the iPhone in the US.,” he says.

The analyst notes that that the U.S. is the only remaining country of the 89 countries in which the iPhone is sold that involves an exclusive agreement. (Some countries, such as China, have only one carrier, but those deals aren’t exclusive.)