Season One is 13 episodes long, but only 12 were actually aired. The reason for this is that the original pilot was scrapped (the other episodes being altered accordingly), leaving 12 to air on TV. However, the series had already been sold to foreign markets as a full 13 episodes. To accommodate this, an extra episode was produced at half-budget: "Epitaph One" takes place in an After The End scenario, stars Felicia Day of Dr. Horrible's Sing-Along Blog (2008) and The Guild (2007) fame. Epitaph One, as well as the original unaired pilot "Echo", have both been included on the Season One DVD.
DOLLHOUSE is part of a FOX campaign called "Remote-Free-TV", which also includes fellow-FOX-show FRINGE. Both shows are expected to have dramatically reduced commercial breaks and therefore more actual screen time.
The company behind the doll houses in the show is Rossum. As confirmed in episode 2.11, this is a nod to Karel Capek's play R.U.R. (Rossum's Universal Robots). The play deals with artificial people, programmed to do work who eventually turn on their masters. This play also introduced the word "robot" into the English language.