Dediu deduced this figure by taking into account recent comments made by Apple exec Phil Schiller during the company's patent trials against Samsung. "Each new generation [iPhone] sold approximately equal to all previous generations combined," Schiller testified.
Dediu used known sales figures of the iPhone 4S, iPhone 4, iPhone 3GS, and iPhone 3G to extrapolate his estimate of 170 million iPhone 5s, based on the assumption that the new iPhone will capture 85% of all iPhone sales.
But Dediu threw plenty of caveats and extrapolations into his estimate.
"The 3G easily outsold the original iPhone. In fact, it sold nearly four times as many," he reported. "The 3GS also handily beat the 3G+original total by a factor of 1.6. The 4 also beat the 3GS+3G+original. As the 4 may continue to sell into the future, the beat will only grow larger. The 4S is only half way through beating the 4+3GS+3G+original." Keep in mind, the iPhone 4S has been available for 10 months, not a full 12. Each of the previous iPhones didn't ship until its predecessor was in the market for a year.
[ iPhone 5 customers will have to get use to some changes. Read iPhone 5 Dock Smaller: Accessory Headache. ]
"Assuming the current quarter's sales roughly equal the last quarter's," continued Dediu, "the total for 4S will reach two-thirds of the sum of the previous generations (i.e. 100 million) by the end of September. Bearing in mind that the 4S is likely to remain in production at least one more year means it has a potential to come close to the target of 162 million."
Bottom line, sure, the iPhone 5 could move 170 million. But it may not. After all, we don't know much about it.
It is expected to have a display that measures about 4 inches, LTE 4G (for which networks, no one knows), a faster processor, better camera, and other under-the-hood goodies.
The current thinking has the iPhone 5 making its debut in mid-September and hitting store shelves shortly thereafter. Given the competition from the likes of Samsung, potentially Nokia, HTC, and others, the sooner Apple get's the iPhone 5 to market, the better.
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