The Ghost of RubangB on 22 May 2009
PS3 has a smaller game library than the PS2, so more people are willing to try out a critically acclaimed sequel of a franchise they haven't played before. Also because of this, MGS4 has less competition than MGS3 did, so it's easier for it to rise to the top. And since MGS4 was on a newer system maybe people who only played 1 or 2 of the earlier games wanted to see how MGS would be done differently with more powerful hardware and graphics.
