How do tv stations know the ratings?

Question

Like when they say 12 million people watched CSI last night how do they know that? Can they monitor what everyone is watching?

Answer 1

They go by the Nielsen Ratings system, surveying people for what they're watching. It's actually pretty inaccurate, though, since the Nielsen ratings don't count for DVR or TiVo-d (recorded) shows.
(Like, many people watch 2 shows at the same time by recording one, but can only list one in the ratings.)

Answer 2

Nielson still has their ratings systems going and they poll a section of the country. The networks pay for the privledge of getting those polls..
However if you look at say the Scifi channel and their ratings they add stupid shows, like Desperate Housewivies, that have nothing to do with Scifi but add them into the mix.
When I emailed Nielson and ask them how could that have happened. They told me they give Scifi.com the software but its up to Scifi management to put whatever shows they want. So its an imperfect system at best.

Answer 3

They go by the Nelson ratings. Nelson is a company that provides free cable to households that allow their boxes to be installed. Their boxes monitor everything that is on all of the TV's within the house. Nelson ratings tell us who is watching what, when & how long.

Answer 4

Not totally sure. BUT. I did a study once with our local cable company for a week. I had to write down every show that we watched in the house that week. Then they tally it for ratings/info.

But now adays I assume they could probably tell with cable/computer. Very good question.

Answer 5

A mainbase that controlls cable or sattelite TV knows what channels everyone is watching and the TV companies pay them to find out how many people watched there channel at that time.