@pezus
This is exactly what I am talking about. The members on this site are woefully unequipped, and terribly uninformed as to just basic trends. Honestly if I wasn't willing to divulge how I was able to determine the failure rate. I am plainly not likely to divulge my favorite methods for tracking console usage. Needless to say however there are many with obvious pluses and minuses. That said I am disheartened to find that I should be asked how to do this on this site.
When I first came to this community it was just routine to see users rigging up their own statistical models. Using multiple data sources. Some used Xfire, or Nielson data. Personally I prefer to crunch the data myself. I am a firm believer in observation effecting the outcome. When someone is aware their usage is being monitored they tend to change their behavior. So I prefer to use data sources which are obscure. However if you just want a link to use here is one. I wouldn't recommend the source mind you, but you wanted a source.
http://www.pcworld.idg.com.au/article/371749/nielsen_xbox_360_most_used_console_wii_most_played/