Link: http://www.gamedaily.com/articles/news/wii-usage-consistent-yearround-says-nielsen/?biz=1
No one can deny that the Wii has been incredibly successful for Nintendo, but every once in a while a comment appears from an executive or analyst to the effect that the Wii is more like a toy that stays in the closet more often than not. One such comment came from Sega A&R's head of content, Darren Williams, who said recently, "I think on one hand the Wii has become the most expensive board game on Earth - it's the kind of thing that families will play at Christmas, and probably won't play again throughout the remainder of the year.
GameDaily BIZ has obtained new data from Nielsen Games, however, that actually shows Wii gameplay habits to be quite consistent throughout the year. From September 2007 through August 2008, Nielsen gathered data (please see chart below) that shows the Wii being used between five and six days per month for around 50 minutes at a time. 
Nielsen Games' Marketing Manager Brad Raczka told us, "All next generation consoles (Xbox 360, PS3 and Wii) continue to grow in terms of their overall consumption of usage minutes compared to the last generation. (Xbox, PS2 and Gamecube). We look at this data every month and see the trend continuing. (The console usage comes from the same Nielsen households that produce the TV ratings)."
He added, "The PS2 still has the highest overall usage for any individual console Nielsen measures due to its very large installed base. It should be interesting to see how these usage dynamics might change with the upcoming holiday season, where variables like recent price cuts and the release of various blockbuster titles for the different consoles could significantly change console activity in 2009."
We asked Nielsen for a comparison of the Wii's average usage days and session minutes to that of the Xbox 360 and PS3. The company was not ready to divulge that extra data at this time, but Rackza noted that there are "definitely differences between the consoles, even more so when you break it down by age, gender and other demos."
mod edit (Sqrl)- fixed the chart image, it wasn't showing up =P
