Hello forumites.

I am normally a poster on Giantbomb, but as you can see, a member here- but I don't post a lot.  I do read regularly though.  It is my time on Giantbomb that leads me to make a rare thread.  Whenever I discuss sales, I am more than happy to quote VGC sales.  I did this yesterday in fact and take a look at the responses and I will ask a question after:

• Where'd you get that chart, because it's not at all accurate.  I'm talking US & Japanese numbers, not UK or other EU regions.  Wii is down 50% year over year.   edit : Oh VGChartz.  Dude, that site is completely fake, not one bit of actual good info there.  Look to NPD and Media Create charts for real data.
• Those numbers aren't worldwide or anything though.  They're VGChartz fabrications.
• VGChartz is a complete fabrication, it was made a person who believed he could estimate how much a game sold better than official trackers.

Now, I did not care for an argument over this, but I did say that I believed they are in the ball park and left it at that.

So, exactly how does VGChartz get their figures and how accurate are they, comparative to other sources?  When I defend VGC, I kind of want to have some information.

It is not. It was a part of neogaf first, then it broke away after some argument and gaf is directing hate towards this site because of it.
sales are quite accurate as i believe.

Oh yeah, I have seen some talk on that and it seems like fanboy stuff the way some go on about it.   I have no reason to believe  the data here is wrong, but I want a bit of a handle on how it is collated.

They, just like NPD, MediaCreate, Famitsu, and GFK/Charttrack, gather samples from retailers and use statistical analysis to determine sales. However, unlike those sources VGChartz historic data gets updated and released so everyone can see when we make improvements on data. If you understand statistical sampling, you would know what a small random sample size is capable of generating data similar to a larger sample size.

As ioi pointed out though, VGChartz aims to provide correct data (sometimes it has to be adjusted) that is accurate enough to determine trends in sales. So weekly figures may not be perfect the first week, but as more samples come in the data is refined. The overall sales are very accurate due to the fact that VGChartz updates their data.

While VGChartz doesn't have a sample size as large as NPD, the consistent performance of VGChartz being close to NPD month after month should be enough proof that the weekly sales are accurate enough especially for fan use.

http://news.vgchartz.com/news.php?id=629

@Nordlead
My background is in Marketing,so I am familiar with statistical sampling. I could just as easily ask them to back up the sales data they rely on, but it would result in a pointless, circular argument with minds of the ignorant and belligerent. I value my time too much for that.

@Mai
That is exactly what I wanted. Thanks.

Damn...3 post in, and already challenging the validity of the site...nice!

he's not challenging, he's asking info so that he can be sure of the validity of the data when he quotes it and argues with it.

Can we use profanity in thread titles, now? Awesome!!

VGChartz isn't perfect, however its released sales are usually similar to other trackers when they release their numbers.

The numbers certainly aren't complete fabrications, there is too much accuracy for that to be the case.