The iOS decline in market share should not be given too much importance. The sales of iPhone devices is still growing (up 20% year on year) and the shipment numbers for the second quarter are partly the result of the cyclical nature of the iPhone product. A yearly product announcement schedule inevitably means the weakest sales in the quarter preceeding the launch of a new model.
However, another important factor is that low cost smartphones sales are making up a greater propotion of overall smartphone sales, which is one of the reasons why Apple is widely expected to launch a lower cost iPhone model later this year.
In the press release iDC noted that Windows Phone had cemented its position as the third ecosystem:
Windows Phone posted the largest year-over-year increase among the top five smartphone platforms, and in the process reinforced its position as the number 3 smartphone operating system. Driving this result was Nokia, which released two new smartphones and grew its presence at multiple mobile operators. But beyond Nokia, Windows Phone remained a secondary option for other vendors, many of which have concentrated on Android. By comparison, Nokia accounted for 81.6% of all Windows Phone smartphone shipments during 2Q13.
Ryan Reith, Program Manager with IDC's Mobility Tracker Programs, did note that Windows Phone has the potential to become an attractive differentiator:
"Nokia has clearly been the driving force behind the Windows Phone platform and we expect that to continue. However, as more and more vendors enter the smartphone market using the Android platform, we expect Windows Phone to become a more attractive differentiator in this very competitive market segment."
Longer term context
Q2's smartphone number continue the longer term trends that have seen Android become the dominant smartphone platform in terms of unit shipments.
Android's dominance of the smartphone market is illustrated in the chart below. However, some caution should be used in treating each platform blocks as a single entities in the smartphone space. Consumer experience can vary considerably from the low end to the high end, especially with Android and BlackBerry based devices.
Moreover, Android shipments are somewhat fragmented at platform level (e.g. Amazon Kindle Fire devices), at the release level (Android 2.3, 4.0 and, 4.2), and at the manufacturers level (different front-end UI). Similarly, BlackBerry's numbers include both BlakckBerry 10 and BlackBerry 7 devices.
By contrast both iOS and Windows Phone are monolithic, with little or no internal fragmentation, although even these platforms have some version and manufacturer fragmentation (e.g. Windows Phone 7.8 versus Windows 8).