Higher userbase doesnt necessary mean higher sales for software. MGS3 was the 3rd MGS game on PS2, there is such thing called saturation.
Gran Turismo 3 > Gran Turismo 2, Final Fantasy X > Final Fantasy IX and so on. 1st title on a platform often does the best, even if the latter title is superior (like MGS3 is considered better than MGS2, yet sold much less)







