Yet the Xbox 360 has a year ahead of release versus the PS3, I suppose?
Yes. Even with a year extra, the PS3 managed to catch up close to the 360 by the end. 360 dominance was a misconception, usually from US posters, who projected their domestic situation with other regions. EU is Playstation territory and for PS its bigger than US iirc.
Asia is also a place where PS does well and where Xbox is non existent. For instance in Japan PS3 sold 10 million+ while 360 did 1.65 million.
PS4 will get near 10 million, while XB1 has sold 111k.