Yes all the value is there but it's not the way you think it is (in the internet age)

Think how much money there was (and is) in liasing ad agencies with Media buying/planning (this is the department's name)

Think how well the companies will treat you if you, let's say, want to place an ad in the Superbowl, or at a TV prime-time slot

The ad agencies are the true customers of the TV companies. Who do you think gets all the pampering (and possibly kickbacks)?