Just noticed that the NPD number for the PS3 for the month of June is actually higher than VGChartz number for the entire America region.... where as the numbers for Wii and X360 are lower(wich is logical). Also the USA retail Preview was way off aswell.

NPD numbers for June 2010(USA only):

Wii:    422,500

X360: 451,700

PS3:    304,800

VGChartz numbers for 30th may to 3rd July 2010(entire America region):

Wii:    438,557

X360: 520,858

PS3:    248,803

VGChartz USA retail Preview(USA only):

Wii:     381,545

X360:  453,146

PS3:    216,459

So looking at these numbers one can see that X360 number for the America region is higher than the NPD number(wich is logical since it's a bigger region and VGChartz tracks bundles aswell), and so is the Wii(although by a smaller margin). Looking at preview numbers Wii might by a little undertracked aswell.

However the PS3 number for the entire America region is 55000 lower than the NPD USA only number, while it should be much higher. Looking at the X360 difference the PS3 could be undertracked by as much as 80000 for the month June alone. Any thoughts?

Consider that NPD could be wrong also, as they sample retail stores just like VGC.

It is fairly consistent that the PS3 is lower here than NPD... but that is only going from my memory and I know NPD do adjust

Ps3 absolutely undertracked!! Need adjustements!

Pretty sure the same is true for the 360.

AFAIR before this month the 360 was undertracked like 6 months in a row.

But hey I'm not complaining.

Not sure if undertracked is the right word here(my English isn't that good) but the numbers are off. Besides the numbers for May 2010 seem to be correct: PS3 NPD 154.500, VGCHartz numbers for the enitre America region for the same period 187,622.

NPD May 2010 X360: 194,600

VGChartz America region May 2010(2nd to 29th): 206,471

So that's higher than NPD.

sure it is, because you comparing all of America (VGC numbers) to US only (NPD numbers)

Here is the May NPD Thread: http://gamrconnect.vgchartz.com/thread.php?id=112461

360: 179,630

Close enough and in the margin of error, but still lower than NPD

I don't get your point. The same thing happened in the past (last year aswell if i remember correctly) with the NPD number of the holidays (also for PS3) being higher than VGChartz enitre America region. And there where adjustment made on such differences in the past, you're saying wait for 12 months and then things will get adjusted?

Those numbers are from the preview(so open for adjustments). The numbers i used are from the current database(so with possible adjustments) and there the America region number is larger than NPD(usa only) witch is how it's suppose to be. With June PS3 numbers USA(NPD) only is much bigger than the entire America region?