Sources:

ChartTrack: http://www.chart-track.co.uk/index.jsp?c=p/software/uk/retail/index.jsp

Media Control (DE): http://www.media-control.de/games.html

NPD Group (US): http://vgchartz.com/news/news.php?id=740

Media Control (CH): http://www.siea.ch/home_de/charts.2007.45.html

Famitsu: http://www.enterbrain.co.jp/en/c_outline/mark.html

GfK (Aus):  http://www.australianit.news.com.au/story/0,24897,17395502-15338,00.html

NPD's lower

I thought it was 60% before Toy'R'Us and then 55% after they lost it.

Chart Track is 90% of what? England?

It´s 65% without T´r´U I think. :)

@ChartTrack: United Kingdom

Media Create seem to say their coverage is only 57%.

"2 cover features a high data rate and rich source of information

Retail POS data is based on. Data provided by the cover rate is about 57 percent, to cover a variety of business. In addition, prior reservation status, shipping status and digestive conditions, such as nearby secondhand trends data, qualitative information by listening to the stores and used as a complementary materials."

But maybe a Japanese speaker (y-koron?) can confirm?

"データの特徴2　高いカバー率と豊富な情報源

データは小売店のPOSをベースにしております。データ提供元のカバー率は、およそ57％、多様な業態をカバーしております。さらに、事前の予約状況、出荷状況や消化状況、中古動向といった周辺データ、店舗へのヒアリングによる定性情報等を補完資料として用いています。"

Media Create Business Data

Hmm, seems a little bit low to me, but it´s on their site. >_>

Let´s see what y-koron says. :)

Nice idea for a thread, by the way. Can you add links to the ones we have sources for? We can leave Media Create for now until someone confirms.

fkusumot,

Post some links please so we can put the % in the first post.

GfK has a coverage of 96% in Australia: http://www.australianit.news.com.au/story/0,24897,17395502-15338,00.html

I´ve updated the list now. :)