If they included worldwide sales it would be a completely different story. Only in the US is the XBox outselling the PS3. Everywhere else the PS3 outsells the XBox - so much that it is catching up with it in overall sales and has outsold it worldwide every month for just over a year.
VGChartz has worldwide sales from 28th May as:
XBox - 54 million
PS3 - 50.5 million
And the people above who state that a lot of XBox sales are not multiples because of the RRoD, please explain how, despite selling more units than the PS3, the XBox trails the PS3 in installed user base?! What's that, you can't?
And again with the above comments, it is typical that when you mention that some people have gone through multiple XBox's someone comes along and states that they have gone through severeal PS3's because of the YLoD. This is bullshit and is from a Microsoft fan trying to justify their loyalty to Microsoft, or trying to justify their purchase - or could be one of MS's employees. Yes, the YLoD exists but it affects less than 1 percent of the PS3's. I know multiple people who have had multiple XBox failures, but only one person who has had a PS3 failure due to a faulty power supply - caused by their son just yanking the power out continuously! And just to even things out I also know a lot of people who have not had XBox failures!