Serious question because I honestly don't know the answer but I always thought those "Behind the Scenes" vids were staged just like most everything else in porn? I've never understood the popularity of "BTS" scenes but apparently they are big business because so many sites offer them these days. Besides the obvious "setup" that they attempt to pass off as horny spontaneity I didn't understand why a broad who's selling booty on film would be cool with giving the company she's shooting for a freebie on the humble. Just seems like hustling backwards to me. But I'm not in the industry and there are quite a few things about the industry I don't understand. I know that there are some cats on here that worked in the industry so shed some light on this for me if you can.
I remember quite a few girls complaining about this as one of the reasons they had problems working with black producers (mostly Justin Slayer). I think some of the girls actually enjoyed it, though (usually white girls, or chicks they picked up in some of the foreign romps in Brazil and such places). The black American girls seemed most irritated with this practice.
for the big studios selling BTS these days, it's probably written explicitly into the contract.... just like in mainstream Hollywood movies where the stars are contractually obligated to promote the movie.