Makes me wonder if this site is being abandoned.
Honestly, over the past year it has felt like the numbers are just automated sometimes.
They kept tracking the DS in Japan for ages after MC/Famitsu stopped and Nintendo had stopped shipments. The last time they shipped any DS units to Japan (at least enough to register on their financial statements) was the quarter ending June 2012 when they shipped 10k. Yet VGC was still tracking it till the end of 2013. I can't imagine they were getting actual data that led to 15 units this week, but 14 units the next.
There was also an issue with the PSP last year where Nintendo's data showed it doing decent numbers ~20k weekly, but VGC was showing near 1k weekly. Just looked it up, one example, the week ending April 13th was originally shown as 1,129. The current number is 23,117. That continued for a while.
The 3DS has also had a lot of issues. The current overtracking has been obvious for at least three months and nothing was done to fix it.
Then there are the issues where games that haven't been released get sales data and ones that have don't.
It all just adds up to make it look like nobody is actively paying attention to the data that comes out and using it to improve the numbers.