The answer comes in a just-released series of slides from a current patent suit between Apple and Samsung.
Evidence in the trial includes some internal presentation slides, apparently done by an Apple insider making the case that the iPhone, for all its worldwide user base, was in a troubling position moving forward.
Why? Because all - not some, but all - of the growth in smartphones was in low-priced gadgets with big screens.
The iPhone, in case you haven't noticed, is a high-priced gadget with a small screen.
The stats, including the slowing growth rate of iPhone sales, are pretty grim.
You can see them all in a story by Jay Yarow of Business Insider.