This document compares and contrasts the Windows Phone 7 Marketplace and Google Android Market in January 2011. It finds that these two app stores experienced the highest growth rates that month at 30% and 18% respectively. While app overlap between countries is over 97% for both stores, the Windows Phone 7 Marketplace has lower overlap (44-69%) among the top 100 apps in each country, indicating it is easier for consumers to find locally popular apps. The Google Android Market remains the only store with more free than paid apps. While 57 of the top 200 cross-platform publishers released apps for Windows Phone 7, it still attracts fewer developers than Android or Apple's stores.