And why?

Sorry but i couldnt post this on the website thread,dont know why.

.....Listen

In terms of hardware sales, "reliability" goes kind of like this:

Nintendo's company (I forget the name) > NPD > VGChartz

This is to be expected, though. NPD's sample size is orders of magnitude larger than that of VGChartz, which has to extrapolate to a much greater degree. This isn't knocking ioi, either: what he does with his resources is pretty amazing. But this question is almost meaningless.

i got by shipments really.

both are estimates, estimates are for all the time unreliable.

they give you an idea, but are useless as hard data.

Khuutra pretty much said what I wanted to say- it all comes down to sample size. VGChartz does damn good for the sample size it gets, but from sheer magnitude, NPD's got the edge.

Nintendo's tracking company (somebody help me out here) gets absolute statements on how many Wiis or DSes are sold. Maybe Xboxes too if Microsoft uses the service. They can quote it down to the unit.

NPD, obviously. It's a professional tracking firm which charges for the release of full data. For the USA, the large company will obviously be more accurate than a few people with a small sample size.

But then, NPD only has US sales.

NPD is, but that's because:

1. They're professional
2. They only do North America (VG does worldwide)
3. They do monthly, not weekly (if that makes a difference)


VG does weekly numbers for each area of the world so its more fun and more interesting.

Equally reliable I'd say. Both take some hard data and then estimate total sales. Sample size isn't everything if the sample you take is skewed. The bigger the sample the less likely it is to be skewed, but it's not guranteed that you will have a more accurate estimate.

When absolute data has come out for a country or region VGC is consistently within an acceptable margin for estimated sales. E.g. a recent report on PS3 and 360 LTD sales in France showed that VGC was incredibly close with 360 and well within 10% for PS3 (or was it within 5%?). VGC and NPD appear to have a consistently acceptable differential. However VGC doesn't report USA only sales so it's not possible to directly compare. Obviously when NPD is higher than VGC for a given month there is a bit of a disconnect (e.g. 360 sales for Nov '09), but that can happen and the absolute figures can still be within an acceptable range.

VGC data is also dynamic in that figures get adjusted its figures as more data comes in over time (see WE 20/12 where initial report had PS3>1 million but now it's below 1 million). So unlike NPD VGC data becomes more accurate with time.

Also HW sales reliability > SW sales reliability for both NPD and VGC I think.

For the purposes of sales discussions on this website though VGC data is the official data, unless you want to talk USA only sales in which case you have to use NPD for lack of US only VGC numbers. (I'd like to see Americas HW broken down a bit further, like it is with Others).

NPD.

Nintendo Police Department.

:P

NPD's more accurate, but VGC gives you 100x the data and cool online tools to analyze it. From my perspective, it's like VGC is the author and NPD is the fact checker that pops in to let VGC know when an important detail is slightly off.