Somewhere in America, a TV remote control is guarded jealously.
"My daughter was here and wanted to watch something and I said, 'No, we won't watch that in this house,' " said a homeowner who participates in the Nielsen Media Research measurements of television viewing. "I really have an aversion to the 'Survivor'-type shows."
"Survivor" creator Mark Burnett won't be happy about this, but that's a pretty important viewer he's losing.
The 5,100 homes nationwide that participate in the Nielsen metered ratings are probably more powerful than they know. The multibillion-dollar television industry depends on their viewing habits: Ad prices are set and programs -- even networks -- thrive or fail based on them.
Aware of that power, and not wanting any of their participants subject to outside influences, Nielsen Media Research zealously guards their identities. A Nielsen family found to speak publicly about its role is immediately thrown out.
But one current participant agreed to speak about the experience, on condition of anonymity.
The person usually resists telemarketers, but was convinced when approached about this opportunity. Nielsen picks its participants through a formula designed to get a representative sample of the nation's 108.4 million households with TVs. It offers gifts and a nominal payment for participation.
"My whole experience with them has been quite good," the participant said. "It is a very professional organization with well-trained people. They show up when they say they're going to show up and do what they say they're going to do."
Nielsen implanted "People Meters" in the participant's two televisions and VCR. These devices sense, and report back to Nielsen, what is being watched. When someone sits down to watch TV, they input a code with a remote control that indicates who is watching. Everyone in the family has a different code, and there's one for visitors too.
A red light on a set-top box turns green when the code is entered. It blinks red when the channel is changed until the remote is punched again to tell who's watching.
"There are times when the red light blinks and you get tired of it blinking," the person said. "But it's not that big a deal. You press the button and the red light goes away."
Being a Nielsen participant has influenced this person's viewing habits. A fan of NBC's "The West Wing," the person watches the show as much as possible to support the ratings.
"I got a lot of satisfaction," the viewer said, "in influencing or getting my say in what America watches."
The Nielsen company was founded in 1923 by a 26-year-old engineer, Arthur C. Nielsen Sr., who tested products for manufacturers. In 1942, he began measuring radio listenership, and expanded into television as TV became more popular. Nielsen's son, the last family member to work at Nielsen Media Research, retired several years ago, and the company is now owned by the Dutch media company VNU NV.
How important are Nielsen's numbers? At least one broadcast entertainment president, Fox's Gail Berman, admits she has a fax machine in her bedroom that beeps every morning when the previous night's ratings come in.