MS requested Final Fantasy for Xbox 360
Apparently, Square Enix agreed to develop Final Fantasy XIII on the Xbox 360 because Microsoft 'asked' them to.
"The Xbox team has been asking us to have a [Final Fantasy] game developed on our platform. Also, the Xbox 360 console is available in many homes in US and European markets so that was not really a hard decision to make," enthused Yoichi Wada, Square Enix chief.
The game was originally set to be a PS3 exclusive, but following what sounds like a polite request, the publisher instead opted to create an Xbox 360 version for Western markets.
It sounds like the Xbox 360's sizeable install-base also played its part.