Apple this morning is reporting iPhone 4S sales of more than 4 million units in its first three days of availability this weekend, more than twice the 1.7 million iPhone 4 units sold during that phone’s first three days in June 2010.
The company calls it the biggest phone launch in history, suggesting that the iPhone 4S has overcome any initial disappointment over the lack of an iPhone 5 from the company.
Compared to the iPhone 4 launch, the bigger launch number for the iPhone 4S is in part a reflection of the addition of Verizon and Sprint to the lineup of wireless carriers offering the Apple phone now. The iPhone 4 launch last year in the U.S. was an AT&T exclusive. Verizon didn’t start offering the iPhone 4 until earlier this year, and Sprint hasn’t carried the Apple device in the past.
In addition, Apple said this morning that 25 million customers are using iOS 5 since it was released last week, and more than 20 million have signed up for the new iCloud mobile synchronization service that works on iOS 5.
Subtracting out the iPhone 4S sales, that means more than 20 million existing iPhone users have upgraded to the new mobile operating system, and the majority of new iOS 5 users are opting in to the free iCloud service.