Sony marketing is the excuse for everything
Well, it is, to some extent. There's nothing about KZ2 that suggests that it should not sell well. It's a genuinely good game with good MP (and even critical reception suggests as much), it looks and sounds amazing, and it combines sci-fi and traditional themes. What it absolutely lacks is good marketing. I don't know how it was marketed in Europe, but based on TV and print ads in the US, it could have been any 3rd party shooter.
Then again, maybe the genre and the theme backfired, in that it might have looked like any other shooter, but I really don't think that's it. I'm not sure what the PS3 userbase is actually like, but I'm starting to suspect that they are mostly PS2 fans who haven't yet figured out that the PS3 is nothing like the PS2.
There was a ton of hype from the hardcore crowd, and the marketing, well, i've seen a lot of KZ ads. Plus, the amount of coverage it had from the media, was huge.
I think more than a flawed marketing, which maybe is flawed because marketing Killzone isn't that easy, i believe that Killzone simply lacks a certain
je ne sais quoi, it doesn't have a strong selling image around it. Basically, the helghasts are the more symbolic thing about the franchise, but when you get down to it, they aren't that cool, and they are very dark, but not scary, and the glowy eyes aren't nearly as cool as the three dots from Splinter Cell.
Main characters are all shit, so you can't sell them, because they are about as vanilla as it gets in terms of design, and then the world itself is ugly, and there aren't unique weapons or gameplay features, it isn't particularly cinematic, but it's not this bare bones experience either.
The demo probably did more harm than good, and multiplayer keeps failing imo, at being associated with the Playstation experience, so the best half of the game is getting overlooked.
Fact is, Killzone 2 mass market appeal rides all on its stunning graphics, the technology that powers it, the fact that it's a benchmark for the system, but it doesn't have this look, artistically, that simply resonates with the mass market in great length. And Killzone 1 was the same shit, it was supposed to be this benchmark for the PS2, and it was labeled the halo killer.
Man most people who play the game can't even remember more than one or two character's names. It's ironic, because although it has this accomplished look, that is inspired by Jin Roh and other stuff, it's not "appealing", it's not very intriguing.
What i'm getting at, is that, maybe, Killzone just doesn't have that much potential after all. As a major name, i mean.