Sources Confirm GTA IV DLC for PS3 Soon.

[DirtyP2002]

The DLC was the smartest move MS could have done.

1. it was a loan --> MS has a pile of cash, around 20 billion so 50 million won't hurt them at all and it is cash they will get back anyway
2. The Lost and damned was downloaded more than 1 million times --> more than 20 million USD revenue on Xbox Live and the 2nd DLC is still coming
3. They showed the world that they got the "superior" (I know...) version of GTA IV and advertised this well. GTA was heavily associated with Playstation, now everybody knows that this is one the 360 as well.
4. This was an important step for digital distribution and a big plus for Xbox Live

Sony would have done the same, but they don't have this pile of cash.