Being part of a "Nielsen household" has long been a point of pride for people whose television habits are monitored by the Nielsen Company. In exchange for token compensation, these viewers know that their personal taste influences Hollywood and Madison Avenue.
But now that Nielsen wants households to let it eavesdrop on many more activities -- from Web surfing to cellphone use -- how far will people open their doors?
As television watching has waned as a component of media consumption, Nielsen has been trying to retool the way it collects ratings, to keep the figures relevant to the advertisers and media companies that are its clients.
Instead of tracking the TV habits of one set of people, the purchases made by a second set and the Web use of a third, Nielsen would like to track multiple activities of the same people, allowing it to determine when someone saw an ad and then bought the product.
Needless to say, this is a tough sell and raises potential privacy concerns.
"I'm going to go to a home and say, 'I want your TV, I want your Internet, here's a cellphone you're going to use and, by the way, I want to measure your grocery purchases,' " said James M. O'Hara, president for media product leadership at Nielsen. "That's a lot."