hey i usually am on gametraiers.com but i like this site a lot too. i just dont use the forums....

but i noticed something,  NPD numbers for the 360 add up to 5 million and yet vgcharts has it marked as 6 million.

 why is that!?

and did the guy who updates the japan numbers die or something?

thank you. ^_^ 

North Amercia numbers, ndp releases usa numbers.

i guess that makes sense, NPD numbers dont include canada and mexico?

Nope when you see NPD its just the US normally.  I have seen NPD numbers for Canada before but its not reported with the US figures.  To my knowledge no group counts sales in Mexico.

 I also believe the people who run the totals on the front page try to estimate current sales for system so the figures are not a month behind.  NPD reports sales about 2 weeks after the end of the sales period the March figures will be released on Thursday.

 This is why you normally see the Japanese sales figures on gaming sites the data comes out every week.

Also don't forget that whenever NPD releases monthly number 2-3 weeks after the month as passed. vgcharts usually accounts for those weeks.

A few reasons:

Yes, VGChartz.com extrapolates numbers for America. It's typically 10% of the US NPD numbers that are added to the total(s).

They also extrapolate NA and Europe numbers to the week. Right now, the numbers for the Wii, Xbox and PS3 are extrapolated to this past week using the assumption that in NA/Europe, sales were the same for the last period. Once the NPD numbers come out, expect the chart to change quite a bit, if sales for the PS3 and 360 increase/decrease over Febuarys.