In my opinion, GOG's decision to do DRM-free movies was the right one....but that should have come later, after they first secured the following:
*Videogame Soundtracks.
*Videogame Books: Strategy guides, videogame education, novelizations, art books, comics.
*Audio Dramas. Advertise that they are ideal for passing time while playing a MMO.
*Public domain films, such as Reefer Madness.
*Mainstream books, whenever possible.
*New Anime & Manga - stuff that hasn't been created yet, to avoid global copyrights.
*Indie film series, like Star Command.
*CDProject contracting studios to make video content.
*New Hollywood films, before someone else makes a distribution deal.
*Classic films, such as Terminator.
ect...
Basically, GOG should work its way up from the lowest hanging fruit. That means initially gunning for stuff that has nostalgic attachment to gamers: strategy guides, animation from the 80's, and so forth. Once a given tier starts to run dry, GOG moves onto a more difficult segment.