on 28 December 2013
To answer you and Carl directly - our lifetime hardware data is obviously a special case as we get shipment data and can make regular adjustments to our formulas (to represent changing trends as buying habits change over time) and correct older data to stay within a certain range of the shipment data. There is obviously increased emphasis on the lifetime hardware data as it means so much to everyone in the "console wars" and as such it is regularly adjusted to be as accurate as possible but if shipment data wasn't released then we would probably be looking a +/-5% range - which would be acceptable for most normal uses. Let's be honest here - the only reason people care is because the PS3 and 360 sales are quite close, if there was a 20-30m gap then nobody would be moaning about 200k here and there
As for official shipment data - none of us know exact stock levels, exact date ranges used and so on. Manufacturers have been known to play tricks in the past with their numbers to make them look better in one way or another so even these figures shouldn't be taken as gospel. I try to use shipment data as a guide to make sure we are in the right area but with stock being anything from 100k to maybe 2-3m at different points in time and with discrepancies in actual dates used etc then the shipment data is only useful to a certain point. With all of that said - what is the specific PS3 situation that you are refering to, I will take a look into it.
To make a general point - we don't just go in and start changing numbers to match someone else. I don't trust what some "insider" posts on Twitter and neither should anyone else. Similarly, most news sites that publish or leak data usually have no idea what they are actually talking about and often mis-report figures or don't compare the correct time ranges and so on. We have our own data, our own contacts, sources, insiders and I prefer to trust our info as I know where it is coming from and exactly what it represents.
It is quite infuriating when someone insists that our data is wrong because so-and-so said such-and-such when we have 100 times as much information on the subject than they ever will!
I'm fine with recent numbers being estimates as they can always be corrected and adjusted when better data comes in. However, there's only one thing that's always bugged me. The numbers for older systems (sixth-gen and earlier) are pretty spot-on as we've had good data for many years, and we obviously won't be getting any better data than that. However, there's one exception to that rule: the original PlayStation. While the lifetime sales of the NES, SNES, Xbox, Saturn, etc., are all almost exactly what their lifetime shipments are, VGC's list of best-selling hardware has it as having sold 104.25 million, whereas Sony has stated that they shipped 102.49 million. Given how VGC's figures for other older systems are congruent with the official lifetime shipment numbers, the PS1's tally being 1-½ million higher than the official count really sticks out. So, how'd that 104.25M figure come about? It's not really a big deal or anything, but I am curious as to why it alone amongst older major systems has a noticeable difference between lifetime shipments and lifetime sales.
And PS2 here is a lot smaller than shipment... but not many bother with it... they are old and dominated, even 20M error wouldn't make a difference...
And about the other post about other sources... say one that is free and have weekly figures... and a funny forum.