VideoGamer.com reports: "According to figures released today by Nintendo, worldwide sales of the Wii as of December 31, 2007 reached 20.13 million units. Wii Software sales reached 113 million units showing an attach rate of 5.6.
5.6 games per console purchased is quite healthy, but this isn't the story across all territories. In the Americas the attach rate is even higher at approximately 6.9, in Europe and other territories the figure is closer to 5.6, but it's in Japan where software sales are struggling.
Although approximately five million Wii consoles have been sold in Japan only 16.8 million software units have been snapped up by Wii owners, giving an attach rate of only 3.4."