2011 Verizon iPhone Sales: Nine Million or 19 Million?

Of the 25 million smartphones Verizon will activate next year, nine million will be iPhones, says Piper Jaffray analyst Gene Munster. He figures Apple’s handset will make up about 36 percent of all activations for the year–assuming the iPhone launches midway through the March quarter. And 6.5 million of those will likely be cannibalized from AT&T–which, were it to retain its exclusive on the iPhone, would sell 17.5 million. Which means the Verizon deal may not give as big a spike to iPhone sales in the States as expected.

“We are modeling for Apple to sell an incremental 2.5 million iPhones with the addition of Verizon, which may be conservative,” Munster explains. “We are modeling for iPhone units at AT&T to be down 30 percent year-over-year in 2011 as the US mix shifts towards Verizon, and as AT&T subs wait to upgrade their iPhones until they are off-contract and can purchase an iPhone on Verizon.”

Interesting, yeah? There is a caveat, though. If iPhone sales at AT&T remain flat year-over-year in 2011, Verizon may see as many iPhones next year as its rival did in calendar 2010. And that would add another 10 million units to Munster’s 2011 iPhone estimate. So: Nine million or 19 million.