They're really pushy about it too. They selected my house and sent a gift basket and some guy came to the house three times emphasizing the "prestige" of being a Nielsen house because you're supposedly helping to define what shows get made. I can't imagine what kind of person would be swayed by that argument.
My uncle used to tell a story about taking a studio tour in the 1960s where part of the tour was being a test audience for Lost in Space (he was a kid at the time). The whole family had a pad with a dial and you could turn it one way to display approval and the other to give a thumbs down.
He hated the show and tried to indicate as much throughout the showing. But when the lights came back on he realized that he'd had the pad backwards the whole time.
He never forgave himself for that one time he "got Lost in Space green-lit".
I could see it being compelling decades ago. Nowadays, though, I'm guessing fans of niche programming are increasingly cord cutters who don't need Nielsen to ensure their TV consumption is being tracked.
Totally non-scientific evidence: The only acquaintances I can think of who still have cable TV subscriptions do so because their TV consumption is dominated by sports.
