Has that number changed much over time? The iPhone 3 hasn't been for sale for over 2 years at this point, so I'm curious if you're seeing the number go down at all.
Not everybody can afford a new iPhone and buying one second hand is a way for people who can't afford a new one to get one. It is entirely possible that those number stay right around where they are at because of 2nd hand users.
What are you referring to when you say the iPhone 3? I'm assuming a typo but not sure if you meant the iPhone 4 (on sale for 2 years) or the iPhone 3GS (on sale for 3 years and oldest version to support iOS 4.3 and up).
