By using this site, you agree to our Privacy Policy and our Terms of Use. Close
bluesinG on 28 August 2008
Edit Thread
Griffin said:
Louie said:
We always said the Xbox 360 is very popular in some parts of America. Every month we have these "Xbox 360 overtracked" discussions after NPD numbers come in, hopefully some people will understand why the console is "overtracked" most months.

Interesting numbers!

Then why do we always undertrack PS3 numbers compared to what NPD lists, unless the PS3 is selling negative numbers in central and south America

VGChartz does not always "undertrack" the PS3, compared with NPD. As I posted in another thread, here are the monthly VGC and NPD estimates for the PS3 in 2008, so far:

  Jan Feb Mar Apr May Jun Jul Tot
VGC PS3 182 305 318 330 178 332 180 1825
NPD PS3 269 281 257 187 209 405 225 1833
Difference -87 24 61 143 -31 -73 -45 -8
Percent -32% 9% 24% 76% -15% -18% -20% 0%

All table entries are in thousands of units. NPD entries are the NPD monthly estimates for the USA only. VGC entries are the VGC North America estimates, scaled by 90% to estimate the USA only. VGC entries are taken from the VGChartz "official NPD threads," and so do NOT include any adjustments made by ioi AFTER release of the corresponding NPD estimates. A positive entry in the Difference row or Percent row indicates that a VGC estimate was higher than the corresponding NPD estimate, while a negative entry in one of these rows indicates that the NPD estimate was higher.

So far in 2008, there have been NO SYSTEMATIC DIFFERENCES between VGC and NPD estimates for the PS3. Single-month differences between the VGC and NPD estimates have tended to cancel out--almost perfectly--over time, as indicated by the essentially identical VGC and NPD entries in the Total column.