I had originally thought trans-media was a buzzword for online content, but over VERY expensive drinks at the Martinez Hotel bar in Cannes, ($27 for a martini? Incroyable!), I got a lesson from producers I met from South Africa and Brooklyn. It's not merely something that's suitable for movies that come from or will become video games.
Zaheer Goodman-Bhyat from Cape Town, who's produced a new version of Athol Fugard's masterpiece "Master Harold and the Boys" explained to me that trans-media expands the content of a film so that an audience becomes more engaged with it. In the case of his film, the trans-media content will be historical and political context, since the play is set in apartheid South Africa. It's not just for shoot'em up games on Facebook. Though, he pointed out that the most popular online game now is not a first person shooter but Farmville on Facebook played by 80 million Facebook users. Trans-media's an element of storytelling on film that can't be ignored, but it's actually being invented right now. We're really making it up as we go along.