Nintendo announces they sold 400K WiiU for the whole black friday week, and then we have the chart showing 448K, 48K more, DAFAQ?!

M$ announced they sold  750K  360, and we have on the charts that it sold  838K; 88K more, how is that possible? I dunno

But when Sony announces they sold 525K PS3, we have on the charts 447K, 78K less.

Judging by Sony numbers, VGchartz is taking the numbers to be sold to the stores, and not the customers.   So the most this consoles could have sold is the amount the companies shipped which means 750K for the 360, 400K for the WiiU, 525K for the PS3  but we have in the charts that the first 2 consoles mentioned sold more than they shipped.

Is there something I am not taking into consideration?? If there is a logical reason for this can anyone care to explain?

Their method is to guess using sample sales from certain stores. They don't track every store. It's kind of like a poll. Depending on which stores they sample, they can get a very accurate picture or a very skewed picture.

Remember those political polls that said Romney was ahead of Obama and then Obama raped Romney? Same thing. They just give you a good idea. It's normally a ballpark figure until the official numbers come in.

you have been here a long time. you know how VGChartz gets their numbers, if not here is the link http://www.vgchartz.com/methodology.php

i think MS numbers are for the BF weekend, not week, so exaplins why it sold more. as for WiiU i have no idea!! and PS3, well im still waiting for even more adjustments :P

The Wii U and 360 are probably due to North America vs USA

The PS3 is probably wrong (or Sony means something different for sales)

That pretty much sums it up.  Perhaps this will help the OP understand.  Now, we can close this thread before talk of VGChartz bias etc. start popping up.

Yep. 

USA = 1

USA + Canada = ~1.1

Just popping up to say VGChartz bias

SEE!?  I knew it would happen!

read the content too and just not the title of the thread.