Sony needs to step up their advertising campaign for these exclusive titles. Playstation, for the past few years has had higher quality exclusives than X-box or wii/wiiu. These exclusives never sell as well as they should due to lack of advertising and a general "who gives a shit" attitude.
For Sony's sake they better fix this problem. Killzone should easily be selling upwards of 3 million, not stagnating around 1.2.