Ericsson released their annual mobility report this month and there is plenty of interest within its pages.
A few surprises too.
For example, Ericsson reports that platform loyalty is far higher on Android than iOS - 82% of Android owners stuck with the platform when buying a new phone, whilst only 73% of iPhone owners bought another iPhone next time. As these figures are for 2015, that suggests that even the availability of iPhones with bigger screens isn't keeping iPhone users loyal.
How does this fit with the growth of iPhone purchases? That's an easy one to explain. The installed Android user base is significantly bigger than the iPhone user base. As a result that lower percentage of Android users who choose to switch platforms works out to be more actual users than those leaving iOS.
Also driving up iPhone sales was the frequency of replacement: 60% of iPhone upgraders were replacing a device that was less than a year old.
There's an old marketing adage which says that it's seven times more expensive to acquire a new customer than to keep an existing one. Given Apple's value proposition being its focus on the customer, seeing more than one in four of those customers ditching iOS at renewal time isn't a good sign.
Far more worrying, for Microsoft anyway, are the figures for Windows Phone. Around 20% of customers stay loyal to the platform. More than 60% jumped ship to Android.