Windows Phone is currently outselling the iPhone in seven markets around the world. Kevin Restivo, an analyst at IDC, says that those countries where it is selling well are Argentina, India, Poland, Russia, South Africa and Ukraine and a group of smaller countries, including Croatia, that is lumped together in a category called “rest of central and eastern Europe.”

For three of the markets, Ukraine, South Africa and “rest of central and eastern Europe,” there were fewer than 100,000 Windows Phone unit shipments in the fourth quarter in each.  Also, Windows Phone tends to thrive in parts of the world that are traditional strongholds for Nokia, Microsoft’s flagship handset partner, because of the iPhone’s high cost.

Additionally, Windows Phone is reaching 10 percent smartphone market share in a number of countries. It is thought that countries like Finland and Italy the OS is gaining traction because of the popular and cheap Lumia 620.

Overall, IDC says Windows Phone and Windows Mobile devices accounted for 6 percent of the 227 million smartphones shipped worldwide in the fourth quarter of 2012. While Windows Phone made up 2.6 percent of the total year, the analyst firm is predicting Windows Phone to be the fastest growing platform between now to 2016 with a compound annual growth rate of 71.3 percent.

IDC expects Windows Phone to account for 11.4 percent of smartphone shipments by 2016, cutting mostly into Android market share. It forecasts Apple’s share of shipments to grow from 18.8 percent in 2012 to 19.1 percent by 2016, while Android 69.3 percent in 2012 declines to 63.8 percent and BlackBerry will be flat with four percent share.