1/ Even if VGC is different, I thought that VGchartz was similar (in the methdology) to NPD, neither better, neither worse, so, in a way, adjustement is not a necessity because we dont know which one is "wrong" ?
2/ BR will push the PS3 even stronger when Toshiba will completely stop to support the HD DVD
3/ ckmlb, Xbox360 Arcade is everywhere but Arcade is not the top selling Xbox360. People firstly buy Premium/Elite and casuals prefer the Wii ...
1. My understanding of the methodology behind this site isn't exact but as far as I know even though the tracking method may be similar VGCharts uses a smaller sample size. That doesn't neccessarily mean you can't get accurate results though. Heck NPD doesn't include WalMart and TRU so their data also has a margin of error with some estimation. It just means the chances of ioi/vgcharts getting some data that isn't representative of the whole market is possible.
Yes and no. Sample Size is only half the equation. Your formula is just as important. Someone with a drastically smaller sample size could be more accurate then soemone with a larger sample size yet less accurate formular.
However the smaller sample size guy would have a better chance of having a drastic mistake caused by some sort of "polutant" infecting some of the sample data.
After you get some sources the large number of sources is mostly to limit the chances of off shooting a lot because of poluted data.