It's always questionable when the source isn't official, but it's an update on Black Friday sales and the current console war, so it's worth discussing.
According to VGChartz , the PlayStation 4 hit a couple new milestones during Black Friday week.
Firstly, they claim that Sony's new console has sold over 16 million units worldwide and over 60 million games since the system's launch last year. Furthermore, sales for the week ending November 29, 2014 came in at 1,193,346, which isn't bad. Given the holiday rush, it's not impossible that PS4 will hit 20 million before the year is out, although it won't have the benefit of any super hot exclusive software.
Now, there may be some problems with these figures. Many argue that the overall global total is higher (perhaps already closing in on 19 million) but we need the official word from Sony before we condemn. It'll be interesting to see how much Xbox One can cut into PS4's lead after Microsoft finally won a month at retail (November).