Chart: 40% of iOS Users upgrade to iOS 6 in first week.

Here's a fascinating chart I got in the mail today: The adoption of iOS 6 in its first 11 days.

Two highlights:

• Within the first week over 40% of users had upgraded. 
• Almost all upgrades came from iOS 5 users. There is a resistant core of about 11% of iPhone users that remain using iOS 4.

Source: Velti's State of Mobile Advertising Report September 2012