Apple's greatest weakness: iPhone continues to underperform the market as a whole

Apple may have the $4, but there is one aspect of its business that you'll never hear CEO Tim Cook mention: The fact that iPhone sales consistently underperform the global market as a whole. iPhone may be the most popular single phone but it is cheaper $4.

Generally, $4iPhone sales roughly track the market. But the global smartphone market is approaching saturation, and growth is slowing. That's a problem for Apple, because $4.

$4 and Benjamin Wilson crunched some data from Gartner on smartphone sales and published this set of charts showing where Apple is making gains and where it's losing.

• The good news: Apple is out-performing the market in the US, Europe and Japan.
• The bad news: Apple's sales are still in decline in the US, and doing worse than everyone else in China.

Keep scrolling for the charts. ↓↓↓