Straight Outta Compton is the next challenge to the industry’s antiquated notion that “black films don’t travel” (a term used to mean that motion pictures with predominantly African-American casts don’t sell outside of the U.S.) http://www.lawyersrock.com/straight-outta-compton-movie/
It will certainly be interesting to see what happens.
Is a big part of the equation predominately P.O.C films don't have a wide release internationally? If you're only being shown in a few markets wouldn't the gross revenue also reflect a limited release. I find it ironic movies like City of God, Ong-Bak, Dead Snow, Tsotsi, Horses of God, ect. are given the legs to succeed in the American market, but American films with P.O.C are automatically dead in the water internationally.