Well, if it helps, VGC has the US total as of April 2 at 13.5m, when it's really at 13.35m. So ~150k over in US.
2014 LTD on VGC is 6.84m, while it is actually 6.68m, so LTD 2014 in the US is over 160k.
2015 LTD on VGC is 12.53m, while it is actually 12.39m, so LTD 2015 in the US is over 140k.
Germany LTD at the end of 2015 is 2.8m http://www.playstationlifestyle.net/2016/01/21/report-ps4-vs-xbox-one-sales-in-2015-in-france-germany/, and VGC has that at 2.635m. That's actually under by 165k.
In the same link, November + December sales in 2015 were 570k, and VGC has total sales there at 566k.
France is in the same link, however, the numbers in that link are sorta outdated in that the numbers were readjusted. Actual sales at the end of 2015 are 2.18m and VGC is at 2.157m. Under by 23k.
UK and Japan are pretty close, and doesn't need to be looked at.
Looks like the over estimating is coming from NA and other contires within EMEA.
i don't really care about the regional numbers. We have NPD and outlets in Japan for numbers. the ROW numbers are pretty much up in the air. What I do look at though are shipment numbers
The old Shipped=sold eventually thing.
If at the end of March Sony had shipped 40M units. That means Sony makes/ships on average 1.4M consoles every month. Some months more and most months less.
It also means that as of the end of April that number has probably gone up by another 1.2 to 1.4M unts. Putting the new total shipment at 41.2M or 41.4M.
Now as of the end of January Sony announced actual sales of 36M or so. That's a sales average of around (surprisingly) 1.4M/month. Now we all know that most of the sales happen in the last 3 months if the year so the average monthly sales of the PS4 is probably around 800k to 1M on non end of year months.
In the 4 months of this year it's thus safe to estimate that the PS4 has sold 4M consoles so far. Which pretty much ensures that total sales are currently above 40M and there are still like 1.2M PS4s in the channels.