Linear TV viewing means watching TV live, as it is scheduled.
The research firms collect their viewing data from a panel of consumers across the country who attach a small box to their living room TV set to record what the household is watching (Nielsen also asks some panelists to fill out a diary of their media consumption habits.) The results are then weighted for the entire population.
But Patrick Walker, the former EMEA senior director of YouTube who is now the CEO of the Rightster multi-channel video network, says these figures are "misleading."
In response to a question from Business Insider about where Walker sees TV viewing going in 10 years, he said advertisers and the wider media industry should take linear TV viewing figures with a pinch of salt.
Walker said: "It's very misleading to say TV is being watched for 4 hours a day. It's on, but it's kind of like, in some houses, like Grandma in the corner: It's there for you when you want her, but you don't really pay much attention. You have all these other things happening on the device so, even if that TV is on, who's to say it's not tuned into Netflix for 2 hours a day? In North America [some research states that Netflix users stream the service for 2 hours each day] you can't have both Netflix on for 2 hours a day, and TV for 4 hours a day ... the maths doesn't work."
The Nielsen Company
The premise Patrick is proposing here seems to be that the TV could still be playing a TV channel in the background, but the screen is actually showing content from another device that's plugged into the TV set: That could be Netflix, or the Xbox, a catch-up service like Sky+, or a DVD. And that's not to mention the fact that the TV might be on, but people on the couch are distracted by their smartphones, tablets, or simply other things that are going on in the room.
The media and advertising industry has made repeat calls on measurement companies like Nielsen to improve the data they collect about non-traditional TV viewing - online, on catch-up services, or gaming consoles, or on mobile, for example. Last year, Philippe Dauman, the CEO of Viacom which operates channels including MTV and Nickelodeon, even attributed its rating declines to Nielsen which he criticized for failing to keep up to date with the way people now watch TV.
Walker thinks more and more homes are shifting away from linear viewing. They may still use the TV set to consume the content, but consumers are taking control over when they do it: "It's more likely to be on demand than linear and live, unless it's a live event or a sporting event. There's no reason why - and Netflix has proven this - that you have to wait ... episodically for things to come out week by week. I think, and Netflix has show, you can still get a massive benefit from series dropping at once."
Walker said: "TV is part of the amplification. If you do something [in digital] you may need TV to broadcast the fact you've done it. TV I think is going to be a major place to spend. You do get massive brand association [uplift], and brand warmth if you do it right, but you should be prepared for that to be an older audience as years go by."
Walker described how broadcasters have been slow to move into the online video space, despite the fact that younger consumers are increasingly spending time there.
He said: "I'm a really big critic of many of our partners! I actually gave a keynote speech at the NBC Universal retreat in California and I've been in front of them [when I was at Google] with some of the biggest checks you can imagine, offering them to come to work with YouTube. And they said no. And now they're basically told to get in line with the basic revenue share deal like a standard [YouTube] creator. And YouTube is justified in that, to say: 'You know what? You missed the big check ... you're no longer that special.' It doesn't mean they can't work on those platforms, but they can no longer site and demand special treatment."
But broadcasters, rights holders and brands are starting to get smarter when it comes to getting on board with new platforms.
Walker said: "There was this large lag between a new platform launching and brands and rights holders wanting to get involved. It felt like the lightning flash and the thunderclap. YouTube launches: Thunderclap. Lightning flash, five years later, brands finally care. Now a new platform launches, and it's like three months later brands are wondering how to get involved."
That has been no more evident than with Snapchat, the photo-sharing app popular amongst a teen audience. Its recently-launched Discover section hosts content from major publishers including Vice, Cosmopolitan and the Daily Mail, and big brands have been paying huge sums to sponsor the different channels.
Last week the world's largest advertising agency holding group WPP, and The Daily Mail, partnered with Snapchat to launch an ad agency.