Let's be clear. I think the concept behind VGChartz is a wonderful one - freely available data to let everyone see how well games are selling. And it's absolutely true that all data is an estimate - not even major services such as Media Create and NPD get it exactly right.
But VGChartz is staffed by amateurs working in their spare time to estimate sales, and while they are perfectly smart, they are much closer to the SimExchange model of estimation than the Media Create method.
What I'd like to see is some clear labeling of what is estimated data, and what is extrapolated or changed from companies that have greater access to retail sales. And not only does VGChartz have no intention of doing this, it is starting to claim major scoops based on data which, in some cases, estimates entire territories without any real data.
In particular, the site widely and loudly disseminated to the media its
worldwide Day 1 Metal Gear Solid 4sales, explaining:
"VGChartz can exclusively reveal that first day sales of Metal Gear Solid 4, released on June 12th 2008 in most major markets worldwide, were an impressive 1.3 million units."
The headline actually
originally read 1.5 million, but was changed by a not insignificant 200,000 units after publication. Even more surprisingly, the figure debuted just 48 hours after the launch of the game - not a lot of time to compile data from retail sources.
I asked Brett Walton about the change, and why this figure was not advertised a little more prominently as an estimate, given the short amount of time to get real data, and he explained:
"It was based on first day Japan sales, first day America sales, and from that projecting for Europe / others which we didn't get direct day 1 for. We projected Europe would be ~20% higher than America given the larger install base and based on previous game releases, but it turned out at 430k for the week vs 510k for America - whereas we estimated it at more like 600k given America and Japan figures."
Firstly, Walton freely admits the numbers were based on zero actual data for the entire European market, just pure extrapolation. It's also very unclear how far the estimates for launch were based on real retail data for Japan and North America.
It's a reasonable figure, of course, because the VGChartz folks are smart people. But it's not a real figure. It's a educated guesstimate, and it's much more of an estimate than the subsequent Chart Track data for the UK, for example. Walton clarified due to my complaints:
"So yes, maybe we should be clearer with the word estimate, especially in early PR and this has been reflected in comments back to the guy who wrote the story. From now on we will label day 1 sales as preliminary for that very reason."
But that doesn't really change the main problem with the site. There's a place for a resource like VGChartz, but it'd be a site that clearly labels the source of its estimates (whether it be Chart-Track, NPD, Media Create - even if some of those sources have poor data dissemination and a fractious relationship with the media) and then labels which are its own estimates based on its own industry knowledge and whatever channel checks it has.
But if I was a writer or analyst trying to extrapolate significant information from the resource, especially regarding those titles which don't chart regularly, given the major discrepancies with other figures shown here, I would not recommend it.
Wii U/ PS4 got similar games though" 
Theres no double standard. Im not sitting here saying Sony's word is reputable and Microsoft's isnt. Im asking why you're claiming the 3rd party isnt reputable, other than you dont like the numbers.