Well they just released the 5s and 5c and the 5c is doing generally horribly - they just cut huge production even with the holiday season quickly approaching.

If you have read Jobs biography it answers it for you. I will try to find the passage.

Basically, Jobs believed that consumers couldn't be making the decisions if there was too much stuff on the market. He wanted a minimal product line where every product was the best. Immense time, energy and focus went into developing and updating the existing products. There was 1 laptop. 1 desktop. As time went on the line grew a bit - you had one power desktop (the Mac Pro - completely updatable, swapable etc) and the Mac Mini. Then you had the 1 iPod, 1 iPhone and iPad.

The iPods were the first line to be diversified but it took a long time. First it was just the regular one and the shuffle. Then they introduced the mini. Each was targeted to vastly different markets - the shuffle wasn't for a different price point, it was for people on the go.

The computer line did the same. They introduced the Mac Pro (the tower) and the Mac Mini and the mid-range all-in-ones. Again, these weren't aimed at different price points as much as different markets. The Mac Pros used to be the only thing you would edit video on. They were easily updatable, enormously expensive but you had 4 memory slots and 4 hard drive spots and more holes for firewire and USB than you could count. You could get 32gb of ram in them in 2005. The Mac Minis were for people who didn't want to fuck around, they just wanted to go online.

They diversified the iPad line similarly - waiting until it was a resounding success and then offering the same thing in two different sizes. This is starting to get away from Jobs though because there really isn't a reason to have two different models besides to keep the brand fresh. The difference between how they split the iPads and how they are now splitting the iPhone is that the iPads were different sizes. The problem with the 5C is there isn't really a difference - the 5C is just plastic and cheap looking.

I don't have faith in this 5c and 5s business. They aren't for different price points or for different markets (here in the US.) People are saying that the 5C is mostly targeted to Asia to cut out a corner of that market. Some people are saying they are for kids. I don't know.