You're not going to get conclusive proof because the numbers you're talking about are estimates.

es·ti·mate:

- an approximate judgment or calculation, as of the value, amount, time, size, or weight of something.

Conclusive proof exists only in theoretical mathematics, everywhere else we just have evidence. The answer to your question is that there is a difference because they are both estimates. And it isn't a large difference between the two estimates, there is a less than 7% difference. It only seems large to you because you're looking at the absolute difference rather than the relative difference.

Is any of this sinking in?

Because their data was so good to begin with that it doesn't need changing, how about that for a possible reason. Plus like i've said before how do you know what changes have taken place at all? Do you think a multi million company with decades of tracking knowledge would come up with significantly wrong data in first place and when it gets changed it significantly changes the original ltd's?

I'm not saying who is right and who is wrong i'm pointing out the difference in data between the two because my personal opinion is neither npd nor vgchartz is 100% correct and their are possible holes in both their data.

But do they have to be in the hand of retailers or not? Cause a console can already be ordered by a retailer even before it is manufactured. In that case it could be considered "shipped" the minute it leaves the factory but it will still be weeks in transit before it will actually reach the retailer. In that case the difference between shipped and sold will be a lot bigger than when the retailer needs to have physically received the console.

I know all of this so you don't need to go down the dictionary definition route. Well you can talk about the % difference but as the real numbers get higher that 7% difference soon turns into millions. As the ltd's get higher then the difference in % should get smaller not bigger other wise that shows that their is a problem.

Then how do you explain March 2008 when the DS posted a huge number despite no major releases or promotions? That sure seemed like an adjustment. Definitely suspicious.

You're right, neither one is 100% correct. They both know this, because they're both estimating.

If you want perfect accuracy, just do what Fishy said at the start and look at the financials. They're the only accurate numbers in the business. They just won't tell you how many of those units are going to consumers.

I will explain it to you a different way ...

Nintendo, Microsoft and Sony all announce 100% accurate numbers which reflect the shipments of their hardware at a particular point in time; they're legally obligated to provide the most accurate numbers possible so they're very trustworthy. When you're trying to track sales to consumers what you're really trying to track is:

(Sales to Consumers) = (Shipped) - (Unsold inventory) - (unsold systems)

The unsold inventory can include the number of systems that are in retailer inventory, in transit, or possibly in the manufacturers warehouse depending on how the manufacturer handles their accounting. The size the unsold inventory is not a constant value, but it is a number which operates in a particular range depending on multiple factors; basically, a retailer is only going to accept so many consoles and a manufacturer is not going to stockpile years worth of inventory for no reason. The unsold systems include replacement systems and systems that were given away (or possibly sold through untracked channels).

Unless you track 100% of the data at the retailer's end (which no one does), or unless your analysts are surprisingly lucky (in which case they should pick lottery numbers), you will have fairly large errors in your data that need to be adjusted. If you blindly continue on without consideration of what the shipped numbers actually mean in reference to the sold to consumer without adjusting your total and methodology you will (eventually) end up with either a number of systems sold that surpass the shipment numbers, or an unsold inventory that is entirely unrealistic.

Right now your NPD numbers demonstrate (roughly) a 10% error for Wii numbers as of March 31st 2008 ... if they continue with a similar error rate eventually the number of systems they expect retailers to have in inventory will surpass the number of Wii systems sold in a year, or they will have the Wii's replacement rate at an unrealisticly high number (given that the majority of replacement systems are refurbished).

Ok hang on here for a second. I've been told several times in this thread that npd goes back and adjusts their data for previous months if they 'got it wrong' so therefore the total ltd that is released is wrong......yet now what you're saying is they just add it on to the next month to be reported which if that's the case then the total ltd is correct and it doesn't matter if they changed it because will still have the final total ltd.

Oi, I never said NPD's LTD numbers were wrong. I said your use of their statistics to prove VGC inaccurate was wrong.