If we looks at the sales more closely we can see the Xbox is way more popular in the US. even multiplatform games tend to sell a bit better (or a lot better) in the US than PS3 multiplatform games. in Japan, the situation is completely reversed and the Xbox is unpopular by comparasion.
however Japan is a much smaller market, accounting for only about 5-6 mil PS3 users. and the home console market in Japan has been found to be in decay. so while it would seem that Japan keeps things on par with the US, it really dosent, the US sales figures trump PS3's populatity in Japan.
however there is also another reason. a game like Final Fantasy 13 can come out (a popular game in the west and east), and sell 2 mil copies in Japan, 2 mil in the US, and 2 mil in the EU. but a popular game like Uncharted or God of War will sell 2 mil in the US, 1-2 mil in the EU, and next to nothing in Japan. the Japanese arnt buying Sony exclusives, since those games are being made by western developers. so the disadvantage for the PS3 on 2 fronts, both in the US and in Japan.
the reason the 360 is so popular in the US, is simply for reasons that it came out a year before, it was cheaper, it was riding on the success of the FPS genre, it had good marketing, Xbox Live has got a really good rep and Microsoft secured a lot a multiplatform games that were sequels to Sony PS2 exclusives.
however the one region that has saved Sony this gen is Europe. console sales for the PS3 are above those of Microsoft, and the sales of PS3 games here tend to be about the same as 360 games. Uncharted 2 has sold about the same amount of copies as Gears 1 and 2 in Europe. the reason Gears has sold 6 million is because its more popular than Uncharted in the US. and Gran Turismo 5 sold more copies in Europe than Halo 3, Halo 3 came out 3 years ago, and GT5 sold more copies in Europe in about 3 months i think.
