Firstly, congrats to the staff of VGC for their work, great job boys.

i've recently looked the numbers on VGC and compared with their counterparts on NPD, MC etc.

And i think that the release of the ps3 slim tends to biased the prediction.

VGC has a method based on prediction. And prediction works well only if there's an history.

The new ps3 changes a lot of trends on WW sales and the prediction seems to be pretty much difficult.

Example : NPD august, VGC is down 50k on ps3, NPD september, VGC is down 50k ps3,

MC and Famistu week 24th october, VGC is down almost 6k, Nielsen Italy week 42 says

1 (1) Wii
2 (2) PlayStation 3
3 (3) Nintendo DS
4 (4) PSP
5 (5) Xbox 360
6 (6) PlayStation 2

and VGC sees PS3 under DS. And finaly, the gap between sony' shipped ps3 and VGC grows up to 2 millions.

Even with the effect of stock, a explanation of the difference is the difficulty to predict a "new" product like the ps3 slim.

What do you think ?

VGC is not based on prediction....

you aren't supposed to think that, you are supposed to know it.

And also, the reason NPD and VGC are different is because NPD is USA, VGC is North America

The ... indicates awkard silence here as he realises his post is completely wrong

Estimates =/= Real sales.

Maybe VGC often undertracks PS3, but in the end, they still adjust numbers in the range of other sources.

I am a bit surprised as Vg Chartz is ALWAYS in line with the other 3....but anyways who knows

EDIT:

this is regarding Japan sales this week

Munkeh111

So you're saying the difference is normal beacause vgc tracks North America and NPD only USA, and you find normal that VGC is under 50k despite counting USA AND Canada...

who said NPD is right? I've seen publishers claim that NPD can be wrong by up to 20%. (and I'm too lazy to track that quote down)

I find the difference normal because VGChartz lands within the weekly accuracy that they expect and constantly corrects their numbers as new numbers come in (like financial results or more stores report sales).

Munkeh11 implies it.

Excuse me but I find weird that VGC is under by 50k whereas they are counting Canada in extra.

I am not complaining I just give my opinion.