sony isn't aiming at microsoft only. they combating nintedo with games.
modnations racers it's clearly trying to rival m. kart wii with a higher quality and bigger budget game.
considering the first party machine sony have turned into, they have managed to do it quite well as far a quality concerned, but their games generally always around 2-4 millions.
but they have many, more than nintendo and microsoft.
i think sony problem it's they don't know how to market or hype their games, they mainly pick the attetion of people who look well into their games, but never expand much from there, after they are done with the game, they change for the next one,
infamous wasn't released and they went for uncharted 2, totaly neglecting infamous.