theprof00 on 11 December 2009
| mike_intellivision said: I think this again shows that NPD has done a great job of convincing everyone of its "invulnerability" when it fact it is an estimation service -- just like VGC. Admittedly, NPD has a large base of data. But it also does not receive Wal-Mart and ToysRUs information. That alone could cause errors, depending upon how the model accounts for this missing information. For example, if you use last generation, Sony could be overestimated. If you use sales of other stores, Nintendo could be underestimated (check out the Wii display vs. the others at Toys R Us). Mike from Morgantown |
It's also a difference in the sample and size.
VGC tracks customers, I believe, whereas NPD tracks the retailer sales.
VGC uses a much smaller sample too, but in some ways, it's more accurate. There will never be an exact number.
I trust VGC.
