People who think that Killzone 2 is a disaster in sales don't understand that game had no chance of selling much better.
It could have done 800K in 5 weeks, but 1000K would be almost impossible. 620K is on a short side -- but just a bit.
I would compare it to Gears of War and Call of Duty 5.
- new ip
Killzone 2 and Gears of War had no brand recognition when they came out. Most of the people who played killzone 1 didn't like it -- so that only lowered the hype. Call of duty on the other side has absolute brand recognition -- the game would sell better even it would have been much worse game
- it's really dark game, Killzone 2 is way more dark for it's own good, there s one glimpse of sun in whole game -- military Helgast race is ugly as it's planet, Gears of War on the contrary had "Destroyed Beauty" -- beautiful architecture in half destroyed cities, Call of Duty 5 has ordinary WW2 setting
-- no co-op
no co-op hurts sales of every game, for people who don't play competitive it means that game has much less value and game time hours, Gears of War had perfect co-op, Call of duty had decent co-op too.
-- it came out in february, hardware sales are not huge to help sales of new software, people generally buy less games, Gears and Cod came out in november
+ best graphics in videogames at the time of release -- Gears of War had that too
+ great game -- Gears of War had that too
+ great multiplayer -- Gears of War had that too
It's doesn't matter how much you market your game -- if the games doesn't have certain qualities it will never explode in sales.
Microsoft marketed the hell out of Gears of War too -- it performed better because it clearly was better game to market. Call of duty 5 is a sequel to 12M+ game -- great sales are obvious.
Now, Sony is stronger in Europe than in US, so Killzone 2 must have performed at least on par with US which means at least 1.2-1.3M WW in 5 weeks. Sony 1st party games always have legs so this game can push 5M LTD.
It's OKAY for this kind of game -- even with this kinda marketing.
To sell 10M Sony needs Gran Turismo 5 or God of War III or Killzone 3.