Copied from nokiapoweruser site:
In Poland, Windows Phone enjoys one of the highest market share of any market worldwide. Recent figures indicate market share as high as 16.3%. Not only this, Poland also have the most active developers writing applications for WP, who create up to 250 applications a month.. This has been confirmed by Marc Toumelin, head of the regional section of the Windows Phone at Microsoft, during the Mobile World Congress in Barcelona.
The obvious reason for this popularity is the traditional attachment of Poles to the Nokia brand. Lumia 610 has been the most popular device in Poland which is a price sensitive market too.