1 million seem doubtfull as there are only 685k players on the leaderboard and the only mode of play is online........
All the official servers are ranked too so highly unlikely many people that bought the game didn't at least play 1 ranked game...
In all likelyhood the sales are actually under 685k as you can have more than 1 psn ID per copy sold...( not even counting rental which will appear on the leaderboard but are not sales..)
So all in all VGChartz is probably not that far of the mark..















