CTV Measurement vs. Linear TV Measurement Explained

7 Min Read

Streaming and Connected TV are cannibalizing linear TV fast—you probably know that already. But what does that mean, particularly in terms of viewership? How exactly do we measure viewership on these various platforms? Read on for a deeper understanding of measuring linear and CTV viewership.

Linear TV Measurement

On Linear TV, shows are aired in a sequential, “linear” order, and viewers have to catch them when they’re on, like Seinfeld in the heyday of NBC (as opposed to Seinfeld on Netflix now, which you can watch anytime). Linear TV still has some value, to be sure: it’s still popular with older viewers and audiences who want to see live TV now, like sports games (though even those audiences are changing rapidly). 

How Linear TV Measurement Works

Linear TV measurement is traditionally conducted by Nielsen, which uses statistical sampling to determine how many viewers we can assume are watching any channel at one time. It does this by issuing Nielsen devices to about 100,000 viewers across 41,000 households and calculating the share of these households tuned into a show at any one time. So if 8.3% of their households are watching The Masked Singer, Nielsen extrapolates that number to be true of all of America.

Advantages of Linear TV Measurement

The advantages of linear TV measurement and linear TV, in general, used to be a lot more obvious than they are now. 

When there were only three networks—ABC, CBS, and NBC—taking a sample of a certain number of households was a relatively representative way of measuring viewer engagement. But as you can probably imagine, things have gotten…a bit more complicated since then. 

Linear TV measurement does give you the advantage of clarity. When you see that the Super Bowl has a rating of 40—that is, 40% of the viewing population is tuned in—that’s pretty impressive, regardless of whether it’s slightly more or less accurate. It explains why advertisers are willing to pay top dollar for a Super Bowl spot: with linear advertising, you can be all but certain you’re reaching the audience that wants to watch that special live show, and that they’ll be amenable to watching entertaining spots. (Indeed, for many viewers, the expensive, high-stakes nature of those commercials are part of the appeal.)

Nielsen ratings can also provide you with measurable gains or losses in terms of popularity. Headlines about the increasing or decreasing popularity of events like the Oscars can be a useful barometer on viewership trends and, thus, the price tag for an ad spot on one of these shows—so you know whether you’re getting your money’s worth.

Disadvantages of Linear TV Measurement

Today there are a lot of ways to watch TV, be it linear, streaming, pay-per-view, and so on. The population is also a lot more diverse than it was in 1950 when Nielsen started measuring TV viewership; for every general demographic set, there are countless interests that networks and brands are trying to cater to. Because of this, linear TV ratings today may only represent: 

• not only a narrow sliver of the population that’s actually watching TV, but also
• a sliver of the population that can’t be extrapolated with much statistical accuracy anyway.

While 100,000 viewers may seem like a good number from which to extrapolate, the United States has a population of nearly 332 million, it seems almost comically like a drop in the bucket. (To be precise, that’s 0.03%. 280 American cities are bigger than this sample size.)

Linear TV measurement is also a simple, binary measure of how many TVs are tuned to any given show. It doesn’t tell you any nuanced demographic information about who’s watching that could make or break a campaign. The ratings of the Super Bowl may seem incredibly impressive in isolation, but how many more viewers consume ads on social media or YouTube? (Look up the view count on any BTS music video, for starters.)

And even if it were more reliable measurement-wise, linear TV advertising is expensive. That makes sense; the purpose of ratings is to price out the cost of ad spots. But with its hit-or-miss nature, the expense of linear TV ads may not be warranted.

Additionally, since linear measurement comes down to the maintenance of Nielsen’s famous viewing boxes, there can be instances of undercounting and inaccuracies in their figures, which happened during the pandemic. 

Ultimately, linear TV measurement may only be giving you a very limited snapshot of viewership—and a blurry one, at that. 

Connected TV Measurement

Connected TV gives you the data advantages associated with the web, and is generally a lot more targeted and precise in its approach than linear TV measurement. CTV is also rising in popularity, with 87% of US households owning at least one CTV device.

How CTV Measurement Works

During a connected TV advertising campaign, measurement works much like web data. It uses third-party data to paint a specific picture of who’s watching, because it’s linked to the device on which the content is being watched, which is usually registered to its user. It’s granular and can determine such elements as impressions (the number of times your ad has been watched) and reach (how many people have seen your ad), as well as conversions (how many views result in sales or other actions). These are possible because the data from a viewer’s CTV device can also be connected to data from their phone and other screens, allowing for a more complete picture of any given content’s impact.

Advantages of CTV Measurement

One of the most important advantages of CTV is that, for advertisers, broad-strokes numbers matter far less than targeted, precision ones. Say you’re a local comic book store. Would you rather advertise on a show that just gets large numbers—say, Monday Night Football—or a more niche show that appeals directly to your particular audience—like Star Trek? CTV viewership information is about reaching the audience you care about most. 

Because they’re more precise, CTV ads can also be more affordable than linear. If you isolate the viewers you want to reach, you can target them more affordably via CTV. And because measurement is targeted in CTV, you can deploy it in service of specific campaign goals—then measure its success. 

Disadvantages of CTV Measurement

On the other hand, one thing CTV measurement can’t offer is the carpet-bombing approach of linear TV ads. When you advertise on CTV, the demographic profile of your ideal customer needs to be accurate. You might miss whoever’s tuning into a network crime procedural this week, but if you know that those audiences tend to be older and that motivated viewers will seek out their favorite shows and catch up with CTV and streaming, you can plan more confidently and still reach your target audience. 

Some unscrupulous CTV advertisers also bundle and resell their ads numerous times, adding murkiness to a field that, in a perfect world, ought to be supremely clear and measurable. So make sure to only go with a CTV partner that offers transparency in how it measures its CTV data.

CTV vs Linear TV Measurement: Differences Summarized

As we’ve established, linear TV is the traditional way of TV advertising and viewing. CTV is obviously poised to outshine it, with billions of dollars being spent on content and 15 million years’ worth of content streamed in 2021 (a pandemic year, yes, but once viewers are hooked, they tend to stay hooked).

Linear TV measurement is an equally old-school affair, measured by statistical sampling. That made sense when there was a relatively small amount of content to choose from and an enormous, less fragmented audience consuming it.

By contrast, CTV measurement is targeted and precise. CTV programmers know exactly who’s watching and engaging with which piece of content or advertising, including the exact frame when they stop watching. 

Of course, your hope as an advertiser is to keep them watching. That’s where working with a company like MNTN comes in. MNTN Performance TV is the hardest working software in television, devoted to transforming your CTV into a performance device that delivers measurable results and success for advertisers who want to connect with the right audience for their brand. 

And working with MNTN on your CTV campaigns means that if you don’t connect at first, you can keep honing your spot and its placement until you do. With MNTN, success is measurable and, excitingly, within your grasp.

TV Measurement: Final Thoughts

With a lot of metrics, jargon, and competition for eyeballs in the world of TV right now, all your choices can seem overwhelming. But they don’t have to be. And by partnering with a company like MNTN, one of Fast Company’s most innovative companies of 2023, you can ensure your TV campaigns are measurable and will get you results.

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