Oh Jesus Mike B will be here any moment... He loves his shipment numbers.
It's quite clear Sony expected higher sales and there shipment numbers reflect this... unfortunately they didnt achieve these sales. npd confirmed this also.
Actually Sony said they won't alter their FY sales estimate, so it's probably on par with expectations.
And yes, worldwide sold to retail data is the most concrete and exact data we can get on actaul worldwide console sales.9
Japan tracking is easy for VGChartz as 3rd party data is usually out before VGChartz data. North American and UK data is harder, but there are usually good NPD and Chart Track indicators, they happen to be the 360's strongest performing markets. Much of interest with regard to PS3 are the rest of the world, where the PS3 performs pretty well.
"...Much of interest with regard to PS3 are the rest of the world, where the PS3 performs pretty well..." Europe is rest of the world? What about Asia, Africa, Latin America...where 360 does well? Do we count those as "rest of the world"?
The PS3 is yet to officially launch in South America, Europe is of course the most important factor, it's a bigger gaming market than the US. AFAIK the PS3 performs well in Asia (other than for just Japan) as well, which is difficult to track as well.
IMO what really matters is that despite big 360 headstarts (1 year for Japan and North America, 1 year and 5 months for most PAL regions to several years for South America, much lower 360 entry pricing and all its most anticpated games already out (including sequels to all well sold XBox games) the PS3 performed well better taking equal timeframes. And many 3rd parties are generating more revenue with the PS3 than with the 360, ensuring healthy 3rd party support, the install base is big enough for a healthy market until the PS3 heavy hitters are out and potentially the release of a cheaper slimline unit.