First off, I don't want to sound like I'm bashing the site. I love VGC, I love that it's free and I love that they make the effort to give us something that we are interested in (VG numbers) and that no-one else wants to provide. I just feel like I needed to say this, because how can VGC ever be a trusted source if they make mistakes like these?
So NPD number come in and we realise that VGC numbers way off. A whopping 42% off in 360's case.
I know VGC is not meant to be 100% accurate. I know the numbers are meant to be in the ballpark of real sales.
But 42% off is not the ballpark, it is way, way, way off. Having a console selling almost twice as much as it actually did makes the number basically unusable, and that's not good for this site.
I've heard several times that VGC needs to update the formula, but it seems obvious to me that the problem is not the formula. The only way you can get a 42% difference is if your sample is small and not representative enough. A few units difference can make thousands of difference on final numbers then.
You don't need a huge sample to get accurate numbers. Pre-election polls are usually quite accurate and the samples are very small percentage-wise.
I honestly think that tracking a 2% of stores could be enough. What VGC needs is a statistician that knows how to get a representative sample with that.
Let's put the US as an example. VGC should not only have a sample in some states and then extrapolate to the whole US. If they have a 2% sample of the stores in America, they should make sure that it is 2% in each state and not 100% in a state and 0% in the rest, for example. Also, that 2% in each state should be shared proportionately according to the different stores in said state (so if 40% of VG stores are WallMart have 0.8% of WallMarts tracked).
What I'm basically saying is, if VGC wants more accurate numbers, it needs to focus on getting bigger and more representative samples and not just tweaking the formula (which can't account for Americans suddenly buying early, for instance). I know this can't be easy, but I it's the only way to have more reliable numbers and less adjustments.
No troll is too much for me to handle. I rehabilitate trolls, I train people. I am the Troll Whisperer.
