James Cameron has directed two installments in the "Terminator" franchise and is now planning to turn "Avatar" into a trilogy since Avatar grossed 1 billion Avatars but has the idea that sequels are made due to hollywood having no originality recycling the plot and charcters to make money wich he has also done himself heres quotes from cameron himself.
"We have a story crisis," he said (translated). "Now they want to make the 'Battleship' game into a film. This is pure desperation. Everyone in Hollywood knows how important it is that a film is a brand before it hit theaters. If a brand has been around, 'Harry Potter' for example, or 'Spider-Man,' you are light years ahead. And there lies the problem. Because unfortunately these franchises are become more ridiculous. 'Battleship.' This degrades the cinema."
And also spoke about how Harry Potter was split into two movies and also Twilight Saga:Breaking Dawn the studio knew it would be able to make more money. He called the move "excessive." Cameron, meanwhile, released "Avatar" in theaters twice, created two separate DVD/Blu-ray editions of the film and is now converting "Titanic" to 3D.