I also think they reduced the price of the console at the right time. It gave them boost in October [they lost NPD month against Halo5, but not by much], then fever rose with the arrival of Battlefront whose bundles pre-sold very well [what a great PR that game got], and then additional 3-day pricedrop for BF. They chained a lot of good decisions one after another.
I't be nice to see what sales of PSN cards and PS4 games looks like for November as that might help us to see if the bundle was part of holiday purchase and the lost profit due to price cut is being offset by additional sales.