Yes, there are many factors, of course. But those factors are in place when an iPhone is released as well. The cell phone user base is large enough that there is always people on contract, off contract, upgrade eligible. So when the phone comes out doesn't affect how it will sell over it's life time -- maybe at launch, but overtime customers needing a new phone is normalized.
That comes back to my initial point that Samsung stock tanked -- similar to Apple's when Q4 2012 iPhone sales were released -- because the S4 isn't as well received as expected and its rate of growth isn't steep enough to make it very lucrative. I think one can infer there is a limited market for large screen phones, and probably not a market Apple wants to tread into until the market proves itself better.
As for who bought the S4, no, I don't have exact #s. I was being hyperbolic lumping the entire 10M into existing just to make the point 10M units in 28 days is good but not great given that it wasn't all new customers. It's a low number considering Samsung has advertised it directly against the iPhone, not other Android phones.
Yes. That is exactly what I'm saying. Every new iPhone has succeeded the previous model in sales by wide margins. You don't get that kind of growth if it's just current customers swapping out old for new. There has to be new, never owned an iPhone customers in there to increase sales, not just maintain them.
