“The combined total iPhones + iPads have overtaken cumulative total iPods. The iPhone started in Mid ’07, more than five years after the first iPod shipped. The acceleration in that product line is still evident while the iPod decelerates gracefully,” Deidu reports. “The total device count has reached 680 million in the last decade.”
Deidu reports, “Tf we assume that account holders typically use one device then by taking the difference between devices sold to date and accounts at that point in time we should know how many devices have been retired.”
More info and the usual excellent charts in the full article here.