2.4 sold to customers VS 2.2 shipped. It can't only be 200k overtracked, it would mean no consoles on shelves/distribution channel.

@ the bolded... exactly, an unusual increase in monthly sales can be indicative of future increased sales, but an unusual increase in weekly sales due to a single game release is far more likely to be a temporary (1-3 week) boost, which therefore throws the prediction off too much.

Weeks of low sales however are not unusual occurences that are unlikely to affect future sales, the only times when there can be anomalous low sales weeks are if a new model/price cut is announced to be happening in a few weeks, so people are put off buying until then (this is generally why price cuts are anounced right before they happen)

Your calculations for each future week are found by comparing the average 2011 week to Vita's latest 2012 week correct? (so for example if Vita sells 35k, while  52 weeks ago 5 platforms sold 500k (average 100k each), that would mean Vita sold 35% of last years average... then you look at 51 weeks ago and see the 5 consoles sold an average of 110k, so the prediction for next weeks Vita sales would be 35% of 110k) The current low Vita sales are not anomalous for any reason otherwise it wouldn't keep selling similarly week after week... which means they are actually quite good for predicting future sales assuming no changes to the platform (price cut/new model/system seller [usually exclusive] game)

You may be correct that the Vita sells over 157k for Black Friday week, but if it does it won't be because the last weeks 33k is a bad indicator of future sales (my bet is Sony & retailers will be really pushing Vita then with promotions and big discounts because it's a hard sell now, that and Black Friday does seem to be becomeing an increasingly important week each year, so I would probably expect an extra 5-10% on top of whatever you get from last years average anyway)

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I just did a quick comparison using monthly sales.

In August PSV sold 142,581 (I believe VGC follows the NPD standard of 4,4,5 weeks for the quarters, so w/e 1st September should be included in September)
Last year 6 platforms sold 3,703,740, which is an average of 617,290. So Vita sold about 23.1% of the average for August
If I extrapolate that 23% to the rest of the year the Vita should sell another 1.4 million and end the year with a LTD of 4,126,024

That's the same calculation as you have used except using months instead of weeks... it helps iron out any anomalous weeks.

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Alternately you could continue using weeks but use a rolling average found from the past few weeks... which means you can still predict the future sales in weekly increments. So you still get the nice curve upwards through November and December, with the tooth of Black Friday in it, but it still irons out any of Vitas anomalous weeks. (It won't help iron out any anomalous weeks the other platforms had in 2011, but the fact you are doing an average of multiple platforms should be helping that already)

I've run a few numbers of my own, essentially calculating the average ratio of hardware sales up to this point to total yearly hardware sales (we're about 47% of the way through the year). That should be a bit more accurate, but it's likely skewed by the fact that the Vita launched this year in the West. Still, it currently shows Vita selling just under 4.8 mil for the whole year, but it's been consistently dropping every week since I think the Persona release.

Yes the midway sales point of the year is usually mid September... Unless there is a price cut or something else special though, the Western launch is going to skew that.

Another workable estimation is to  estimate November being double October sales, and December being double November. (usually slightly over double). Obviously we haven't got October sales to use yet, but they are usually a slight drop from September (actually more sales per week, but September is a 5 week month)

So based on the August sales September would probably be around 5*35k = 175k... then 4*40k for October = 160k... then 2.2*160k = 352k... and 2.2*352k = 774k
That only gives a total of 1,461k though, for an end of year total at 4.186 million
Hmm, surprisingly similar to my previous calculation based on Vita monthly sales.

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I do believe the Vita will ultimately surpass these kinds of calculations mostly because it's a new system and it's first holiday season in the West (and it didn't spend much time in the holiday season in Japan last year either) but unless something changes soon it will struggle to make it to 5 million this year.

I could switch to months but the damage has been done already, besides the massive fluctuations keep this thread lively. Just wait till it shoots up and all the crow will be served to the other camp.

Well switching to using an average across a number of weeks is simple enough.

I mean your formula now is probably something like this:

[week n] = ( [week n-1] / [average of week n-53] * 100 ) / 100 * [average of week n-52]

The bit between the rounded brackets is what works out the percentage Vita is selling compared to the 2011 average... as long as the "week n-1" period corresponds with the "week n-53" period it can be any length you want. I think a period of 1-3 months is best because it doesn't get skewed too much by anomalous weeks but also doesn't go too far back in time including possibly irrelevant data (particularly in the Vita's case as going back more than 6 months would include launch sales)

And regarding crow eating, if the prediction graph shoots up because of an anomalous week, it's only going to come down again in the following week or two.
Looking at next weeks sales for example with Japan at ~50k and the usual 20k in the West: Assuming I am still correctly interpreting your formula your graph is going to be predicting the Vita to more than double the current prediction for the rest of the year, bringing the end of year total to around 5.5 million. Then if past trends in Japan are anything to go by, the following week Vita will be sub 30k in Japan, then sub 15k again the week after and your graph will be showing an end of year about 4.1 or 4.2 million again. (at least assuming there aren't any other special bundles in Japan I am unaware of)

Updated to September 1st

Vita Weekly Predicted Sales 12/22/2011 - 12/31/2012

Vita Lifetime Predicted Sales 12/22/2011 - 12/31/2012

Huge boost in sales mostly thanks to Japan. Hitsume Miku: Project Diva F sold 158k units including sales in a Vita bundle, helping push 49,588 consoles. Numbers are also up in Europe and North America, thanks to the release of Madden 13 also available in bundles. Madden 13 sold 25,264 units of software in NA with 13,865 Vitas sold. Europe sold 13,306 with no Vita software titles in the top 10.

In total Vita sales skyrocketed up 143% from last week.

Dat Vita is saved!

Let's see how long the boost lasts...

Your graph seems to show ther being 2 more weeks of Vita data than we have at the moment (the red line indicates sales weeks already passed yes?)