IGN - PS3 Not Enough for GTA IV
Well it looks like we've got an official response from Phil Harrison concerning GTA IV being the first non-Sony exclusive GTA title.
Originally Posted by Phil Harrison
I don't think PS3 has the install base to support Rockstar's investment in GTA IV on its own.
So basically what he's saying is that Rockstar wouldn't make enough money off GTA IV if it were a PS3 exclusive. The article also talks about Sony's trouble with third-party exclusives (which I won't outline here since this is the GTA IV forum, just read the article). Once there are more PS3 owners, it will be easier for Sony to grab exclusives such as future Grand Theft Auto titles.
Have to agree with Rockstar one this one. Even though there are a decent sum of people who would buy a PS3 just for GTA IV (if it were exclusive to the platform), they still wouldn't make as much money as if they released on the 360, since it's the more popular platform. More owners = more sales.