Americans love violence. It is in their culture, it is part of their history. The 360 focuses heavily on violence and that's what american teens want to do. Not to mention MS has a lot more advertisement going on than Sony.
That's a pretty ignorant statement.. If you look at history as I have (got my degree in history) you'll see violence is present throughout nearly every culture throughout time, at least to an extent. I will agree that American media loves to hone in on violence to boost ratings, but that doesn't mean the American public loves violence.
Also, let's be honest here, is the PS3 lineup really less violent than the 360's?
True that, there are plenty of others nations and/or empires throughout history that have been equally or more violent. The main difference lies in American involvement in so many modern conflicts, the ones you see on the news and learn about in recent history in school, thus the notion that the US is a more violent nation persists.The 360 is just as dominant and important in the UK, perhaps a remnant from colonial times? It is not big at all in old war nations such as Italy, Greece, Japan, France and Spain, so that theory is out the window in a flash.
As far as the PS3's lineup against the 360's; I agree 100%, the PS3 and 360 are nearly the same console as far as library goes.
My take on why the 360 dominates in the US:
First off its a damn good product and they also enjoy massive brand recognition there. Secondly, they had terrific 3rd party support from the beginning, the 360 was lead platform on mostly any multiplat developed from 2005 to 2009, this established a (mostly correct) picture of the 360 getting superior versions of most 3rd party games, the metascores from the period reflect the same belief.
Then there's marketing and Western-centric games, MS spend incredible amounts on marketing and these are bound to have a large impact on sales in the "homeland of the commercial", imagine ball-games, rodeo, monster trucks, track & field, concerts, cinema, TV spots in the middle of hit shows, billboards and countless events that they shell out for to show off their product. As far as marketing is concerned, Sony and Nintendo would do wisely to pick up a few cues (and a clue) from MS. The Western centric games spek for themselves, the 7th generation has become the Hollywood generation, almost all genres and games have fallen into the CoD conventions and mindset.
Superior online; the 360 has by far the best online service and it was honed and ready to go from launch. They focused a lot on online gaming from the beginning, knowing that this would be big.
1: Brand recognition (A trait that Japan and the US shares, especially the parent generation and up will be massively patriotic in their purchasing habits)
2: First class 3rd party support
3: Extensive and Western centric games library
4: Massive advertising budgets
5: Affordable price, especially over the PS3
Note; the above are not in any kind of order, just making it easier to read.