Originally Posted by Opcode
Petitions help the cause, without one they have no drive to release a PC version. A petition alone can influence whether they release a PC version or not. If Rockstar see's that over 200,000 people are looking to buy a PC version of the game. That's a big chunk of change they would be losing out on otherwise ($10 million).
They already know 200,000+ people are looking to buy a PC version. That is why they are going to release it on PC whether or not that petition gets 200K signatures. They didn't need 200K signatures to influence them to bring GTA 3, Vice City, San Andreas, GTA 4, TLaD, TBoGT, or L.A. Noire to PC.
Saying "We are thinking about bringing it to PC" is a very successful marketing strategy for them. 9/10 times PC gamers end up buying it twice because they think it won't come to PC so they get it on console. 4-8 months later when console sales die down, they bring it to PC then the PC gamers buy it again.