Android lost annual share for the first time ever.
During the fourth quarter of 2012, Microsoft's Windows Phone platform replaced BlackBerry as the third leading mobile operating system.
Strategy Analytics also revealed that, for the first time since the platform's inception, Google's Android saw its market share decrease in annual terms.
"Microsoft Windows Phone overtook BlackBerry OS to become the third largest smartphone platform in the influential United States market during Q4 2012. It was the first time Microsoft has surpassed Blackberry since 2006. Meanwhile, Android lost market share in annual terms for the first time ever. Are we now at “peak Android?” Which hardware vendors dominate the Microsoft and Android smartphone ecosystems today?"
While Microsoft launched several Windows Phone 8 devices during 2012's Q4 – spearheaded by Nokia – BlackBerry 10 was being prepared for a January 2013 launch. With reports of initial positive performance for the BlackBerry Z10 smartphone, it'll be intriguing to see the market share for each of the aforementioned platforms once Q1 ends after March.