It was a response to you (clicked wrong button), check edited version. Point is, they're tracking shipping units but still haven't updated MS numbers. 

I completely agree. Although i think vgchartz can be unreliable it usually does give a good indication of where the sales are at. 

 I don't think the problem is the +/-4% deviation but rather the inability to correct the numbers once the accurate information has been provided. At that pace, it adds up and deviates even further making the numbers down right unusable even for estimates. 

Nope. They reported the 3.8 million shipped in a news article, it didn't get incoroporated into the Sony LTD total sales data on this site. VGC estimates global sales to consumers, that's all.

Edit: Up thread it's said the 3.8 million is sold to consumers. I don't know which is right now. I pretty much always assume "sales" reported by the console makers is always shipped to retail.

That makes more sense. I was starting to detect a disturbing trend...

Anyhow, are you certain about this? Nintendo has its own internal tracker: I have a hard time believing that Sony doesn't have something similar. In fact, doesn't Sony subscribe to Nintendo's tracker?

Shipped to retailers and sold to end consumer figures are going to be very similar at this stage. Retailers are not going to buying more units per month/quarter etc than they are selling. As such, Sony would be able to estimate the number of PS3's sold during a week/month/quarter/year to end consumers, even if they can't get it right to the unit.

Also, Sony would be able to judge sales from retailers based on follow-up orders. If retailers buy a batch of 5 million after their first batch, Sony can be sure the PS3 sold quite well. If they ordered 100,000 units, obviously stock (ie the 3.8 million shipment that you are talking about, that may not have even been shipping related) did not sell at all well.

Why are people questioning the reliability of VGChartz sales numbers? AFAIK VGChartz numbers are the real deal. VGChartz sales numbers are 100% accurate retail sales numbers. Never question the reliability of the site's numbers.
Shipment numbers are well in advance of the retail sales numbers. Some times months ahead of schedule. 39 million could be the number of 360s manufactured to date.

Going to repost this as it appears some people missed it.

The discrepancy between VGC's reported figure and Microsoft's sold to retailer figure are the nature of the beast and not due to any intentional number fudging on the part of the site.

Here are a few key facts to consider.

1. VGC can only estimate actual sales due simply to the impossibility of tracking every single sale across the globe. The methodology is similar to that of NPD, Chart-Track/GfK, Media Create and Famitsu. Poll a portion of the retail market and extrapolate.

2. Coverage. Microsoft sells the X360 to some markets that VGC does not cover.

3. Retail channel stuffing. In 2006, 2008 and so it appears this year as well, MS pushes out as many units as possible. Even more than consumer end retail can sustain.

4. Distributors. This is an industry segment not many consider. Technically, the big 3 don't sell directly to retailers but instead to distribution companies that then sell to retail. This is why MS can ship out more product that retail is willing to buy and stock and the largest reason for big discrepancies such as this.

i have been coming here for  long time, i jst dont post very often, cause the crowd here can sometimes be lame

 Yes. Sony has referred industry analysts when asked for sales to end consumer to NPD and such. And there are retailers that will not disclose such information like Wal-mart. Sony keeps track of the units they sale = units sold to retailers. Anything else would be a guess, and publicly traded companies cannot release guesses to the media in an official manner due to investor litigation.