CIRP finds that as of the end of the March 2015 quarter, 94 million iPhones were in use
in the US, including 25 million iPhone 6 and 13 million iPhone 6 Plus models.
By analyzing data on iPhone buyers, their new model selection, and their prior phones, and overlaying Apple iPhone sales data adjusted to the US market, CIRP estimates the number and model of iPhones in use each quarte
“There are still 8 million iPhone 4S phones, dating back to 2011, in use,” continued [Joshua] Lowitz [from CIRP]. “While they are ripe for upgrade, many of these consumers have owned their iPhone 4S for only a fraction of its three and a half years on the market. The size of this upgrade cohort, relative to the number of new iPhone 6 and 6 Plus units sold, suggests that the coming quarters may prove challenging for Apple in the US.”
CIRP bases its findings on its March 2015 survey of US Apple customers. CIRP samples 500 customers that purchased an Apple product (iPhone, iPad, or Mac computer) in the preceding quarter.