The movie on shale gas drilling directed by Gus Van Sant has its international premiere Friday at the Berlin film festival. It is one of 19 films running for the Golden Bear award.
Damon told reporters that the film didn't get "the reception that I would have hoped for" at home but "sometimes people find movies later on."
He says the movie doesn't aim to pass judgment but to explore how decisions are made.
Damon stars as a salesman persuading inhabitants of a small town to sell the right to extract gas.