Ok, it was a mistake to only look at the gap on Q3 2018 and not the entire 30 millions. Plus I have revised my numbers, there are more gap now between sold Q3 and ship Q3.
So Why here we have such a huge gap, but now we would pretend that for 2018, VGC's estimation would be so much better :
FY 2017 ship : 15,06
FY 2017 sales : 13,51
So what gap shall we expect now if projection of FY2018 sold gives us 17,08 (my projection), why before we had 1,55M and now it would be much less ?
You are making the same mistake again. The proper comparison is always LTD sell-through vs. LTD shipments. The key point is that retailers tend to maintain a stock level that lasts them 6-8 weeks in order to be prepared for sudden surges in demand; if they ran out of consoles, a potential customer would do their business at a different store.
A console that sells 250k units per week worldwide will have a bigger gap between LTD sell-through and LTD shipments than a console that sells only 150k units per week. There are times when retailers over- or underestimate demand for a console, so the following fiscal quarter will see a correction due to retailer orders. VGC's estimates point to a slight overestimation, so for the current fiscal quarter sell-through can exceed shipments as retailers scale down the stock they have on shelves and in their warehouses.