Perhaps people have been spending their money on tablets...
Fun how the maturing of the mobile phone market isn't being heralded by the media as the end of mobile phones, like we've been seeing regarding traditional PC's...
Perhaps like tablets verses laptops and desktops, once people have a nice shiny tablet, they discover that they don't really need or can afford a fancy new mobile phone in addition to the tablet - as the fancy stuff is largely handled by the tablet, hence last year's mobile phone is still fit for purpose and in fact that old phone in the bottom of the draw has better battery life...
With practically all major IT consumer device markets reaching maturity we're now entering interesting times as companies will no longer be able to hide inefficiencies behind increasing sales volumes and revenues.