mind share, ps2 owners didn't know who kratos was, ps3 owners know who kratos is, better marketing--> better sales, friends lists, word of mouth and being even more violent than the first two .
5-6mln lifetime
(realistically 5mln)
perfect example
call of duty:finest hour(ps2) 2.8mln units
call of duty mw2 (ps3) 6 plus mln units and growing
why would call of duty sell better on ps3 than it did on ps2?
1) mind share everybody on my friends list is playing it ill buy it too
2) marketing and awareness, most casuals even know about call of duty( not saying the same is for god of war, just saying god of war has more awareness now, than it did on ps2)
3)pretty much makes the smaller userbase argument useless i think, people will buy consoles to play god of war.
"even a dead god still dreams"