Simple answer is because nothing like 10.4 million units have been sold, as many have stated there are a huge amount of units sitting in warehouses and in shops - same with PSP.
VG Charts tracks sales not shipped numbers generally, as in some cases such as this there can be a large discrepancy between the two...
It is well known that MS reports "sold" as "sold to retailer", whereas Sony reports "shipped" as a unit that simply has left the assembly line.
The difference is that the MS total does not inlcude those units just sitting in a warehouse unsold to retailers, whereas Sony's could. Their "sold" number is units that are in the consumer's hand or sitting on the store shelf.
Here's how Robbie Bach phrased it:
"Robbie Bach on how they count things:
Q: Itâs 10 million shipped, right?
A: Yeah. In our case, itâs reasonably close to sold through. To make sure weâre clear, Sony does shipped from factory. We donât. Our shipped means it has left a distribution warehouse in Memphis to a retailer. There is a big lag of six week to eight-week lag between what we called shipped and what Sony calls shipped. Thatâs the way we do the accounting."
MSN stated differently than him. I would tend to believe him, but then again can you believe anyone from M$, Sony, or Nintendo? They lie just like anyone else.
The article on MSN stated "shipped" when M$ predicted 10 million by end of 2006 indicated shipped from factory.
Regardless, if you've been to a BB, CC, Ebgames, etc. This Christmas (or year for that matter) it's obvious that units "in stores" are not necessarily close to sold. Especially at my local BB where there are literally 2 slabs of more than 100 360 consoles, and more in the back.
Now that is anecdotal, maybe not true everywhere. But if you do the math from NPD, Japan, and Europe it's obvious there is a desparity between what is being reported as "sold" and in end users hands.
And despite what some people seem to think. Sold to a retailer is just a bragging number. (Shipped to the retailer means they already bought it, so it's the same difference with about 2 weeks lag time for numbers).
Sold to retailer doesn't mean a thing when it comes to actual success. As I said, the hardware is not what generates profits, it's software, and now online services too (such as movies, or XBL cards you buy at the store). So whether or not it is in the end users hands matters a lot, if it's just sitting on a shelf then it's not making them money period.
When the end of march rolls around, and Sony comes out and claims they have shipped 6 million consoles are you going to be holding this site to same account? Meaning, some people seem so adament about correcting the 360 sales figures, but I can gaurentee you by the end of march the number on this site won't read 6 million for PS3...even if Sony says they have shipped that many.