An attempt to address the declines with the launch of the Microsoft-branded Kin failed – Microsoft pulled the plug after poor sales of the youth-centric smartphone.
The open-source Android has so far proved more enticing to handset manufacturers and developers than Windows Phone's closed-garden approach.
Microsoft chief Steve Ballmer in June admitted the company had missed out on an entire cycle of the handset industry, but said that leadership changes within the Windows Phone software group should help aid a turnaround.
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