Jonathan Klein, a former president of CNN/U.S., speaks with Brian Stelter about the television industry's uncomfortable dependence on Nielsen.
"Ratings rule television. So, really, it's Nielsen that rules television," Stelter said.
Nielsen ratings are what's called the "currency" for the whole TV industry to buy and sell ads and determine what's popular and what's not.
"Nielsen recently admitted to a glitch, a software bug that affected broadcast ratings for months," Stelter said. While the bug was minor, "the incident just deepened the TV industry's mistrust of the company."
Ratings are the "report card" for TV, Klein said, but when he was running CNN, the data never offered enough insight.
"They were a very narrow snapshot of one type of behavior - how many people are sitting in front of a couch watching TV - when, in fact, we know that it's really a panorama. You know, media consumption is about squeezing [TV] in amidst a lot of other things - tweeting, cooking, reading, putting your kids to bed, waking them up, whatever."
"And so, they never felt reliable," Klein said, "and never told us the most important piece of information which is who is watching, and what else are they watching, and what else are they doing, and where else could we find those people, and that's the advantage of digital media over the old obsolete Nielsen ratings."
Nielsen produces viewership estimates for the entire United States population using a scientific sample of 25,000 homes. The company is confident in its sample: "Today," it says, "the ratings are very reliable for the day-to-day, national networks."
The recent glitch affected "a very small amount of total viewing," according to the company.
But when the ratings were corrected, it changed the outcome of the nightly news ratings race - ABC's "World News Tonight" was thought to have beaten the "NBC Nightly News," but it turned out NBC was still #1 among total viewers.