On Demand question - DirecTV

I was looking forward to watching the OnDemand feature on Directv because the commercial had said enjoy thousands of movies and tv shows for free. I go to watch certain movies and shows and it says I am unable to unless I subscribe to HBO, Starz, Cinemax, etc...The commercial and ad's are very misleading if that is the case and it almost borders on false advertising. Am I doing somethnig wrong or is there a way I can take advantage of my OnDemand without having to pay extra for all those movie channels?

This question, "On Demand question," is about DirecTV channels, programming, equipment, and sports.