It doesn't.  I guess some people just want the numbers to be more overtracked than they really are, hence making the weekly numbers MUCH smaller.  Here's the real math.  In the Wii's 2nd Xmas, it sold 1.1M in the corresponding weeks we have left on VGC.  Right now, VGC has the PS4 at 18.2M, so 300K left to reach 18.5M.  It's obvious the PS4 didn't match the Wii's sales, so let's say it sold 900K-1M in those last weeks.  This makes it just as you said, 600K-700K overtracked.

Lmfao the way some are talking about 1 Million overtrackedz is ridicolous like it changes anything in the long run.

last report, sony gave specific numbers for ps4 only
doubt they will change that again. so we will get shipped numbers form sony for sure

and this quarter, maybe even ms will give us xb1 numbers, because it will not look horrible like the last two quarter.

From neogaf. Good numbers.

Software: 81.8 million.
Hardware: 18.5 million

Tie ratio: 4.42

Something doesn't add up...

Geoff Keighley said "Sony has announced 18.5M PS4s sold through worldwide to date, including over 4.1M between 11/23-1/4".

Reuters said "sales of its PlayStation 4 video game consoles exceeded 18.5 million units as of Jan. 4, up from 13.5 million at the end of October".

That means from November 1 to November 22, they only sold 0.9 million (18.5M - 4.1M - 13.5M), or 300k per week? That sounds too low for November. November numbers are usually 1.5x October numbers, and not 1.0x October numbers.

I think we'll have to wait for the end of the quarter financials to know for certain.

ps4 is at 900k this week
next week is the christmas week ( that could be either the #1,#2, or #3 biggest week of the year)
it all depends what day christmas eve is exactly in that week

so its either going 10% down or up form this week (just as a rough estimate form previous years)
that alone would result in 800-1000k ps4 next week
right now the ps4 is at 18.25m

the week after christmas should be a 30 - 70% drop off

so it's actually ~1m overtracked +/- 200k

the 13.5m numbers form reuters is shipped (and even that number was end of september, not october)
some1 got something wrong

I think it will take a while to hit 20 million. So they made this number. Plus I have seen many sites comparing Xbox One 10 million shipped and PS4 13.5 sold and neglecting actual difference. So Sony wanted to diminish this. Plus its good for company image.

I think XB1 might have actually won November.

No I meant November worldwide. I don't think rest of world made up the difference from NPD.