The second type of market:
Metered Market: These markets use a set top box to track what people are viewing. When you turn on the tv you enter your code so the machine know which person in the house is viewing the shows. Much better than a Diary market, but does not easily keep track of how many people in the house are viewing at once or if someone leaves the TV on and leaves the room.
The last type of Nielsen market:
Local People Metered Market: These markets use Nielsens newest system. The box in the house can keep track of who is watching the show, and if the person is in the room. As people walk in and out of the room the box tracks who is watching and which demographic they fit into without user input. This system was going to be spread across the who country, but since it was very expensive to implement, Nielsen pushed the cost onto the local TV stations in a market and the Companies that subscribe to Nielsen. With the huge increase in prices many stoped subscribing to Nielsen and the roll-out slowed to a halt.
Rentrek is the new tracking company that is slowly building up steam. They are much cheaper to subscribe to and have a larger sample base, because they track every cable box in a market. They do not have to pay their sample base either, because they do not put special equipment into the house. Though many media companies are afraid to switch over, because Rentrek only looks at houses that subscribe to cable but not houses that only receive over the air TV.
