At a recent International Advertising Bureau (IAB) video event in the UK, over 80 percent of participants said time spent with the brand – or attention – was more important than Gross Rating Points (GRPs).

In case you weren’t aware, the GRP is a measure of the reach of a campaign and how often people saw it. For example, a campaign reaching 12 percent of the total population with an average frequency of three exposures has 36 GRPs (12×3).

GRPs have been the standard measure for TV audiences for decades being well suited to the sheer scale of linear TV viewing. They also provide nice simple planning assumptions: Spend = Reach (%) X Frequency X Price

Basically, if you want to reach more people you simply have to spend more. If you want to keep your spend constant but still reach more people, then you either need to reach them less often or buy lower-priced media.

This simplicity has allowed brands to deploy significant budgets against TV for decades. If you deploy significant budgets, it shows up in econometric models and it then becomes possible to demonstrate ROI and, therefore, justify spend.

Consequently, due to the natural inertia of industries, it’s easy to see why planners also want such a simple measure for online video that de-duplicates the increasingly fragmented way people watch content and ads today and provides simple assumptions about changing spend.

However, a single metric for online video comes at a price. You can’t differentiate between the unique methods of engagement and receptivity to advertising on different devices, content types and contexts. Also, online advertising rarely has the weight of familiar econometric models behind it to meet the second element.

GRPs are also useful for a third reason. They come bundled with audience demographics – a very familiar metric (known as targeted rating points) allowing brands to understand and buy a specific target audience.

Consequently, online video has bent over backwards to harness a metric that makes it easier for TV advertisers to understand and spend online. But herein lies the fundamental problem in transposing a TV metric to an online environment – it misses the vital point that what a consumer is interested in is more important than their demographic.

I’ll use a white goods anecdote to explain. A white goods manufacturer assumes it should target women aged 20 to 60 because that’s whom they sponsor and that’s who will turn up at their events. However, if you ever go shopping in an electronic store or a mall you’ll find that it’s everyone else too. So, planning for only to 20-60-year-old females, the white good manufacturer would miss all these other groups. Instead, the manufacturer should plan to reach all people interested in home appliances. For scale, they could expand to those interested in electronics, then for any users interested in shopping.

The GRP was born in a time when TV was viewed on a single household device, when there were relatively few channels, and a limited number of set piece shows and events. Today’s world however is big, noisy, cluttered, and connected. It’s simply not feasible to treat digital video the same way we treated TV, something more and more marketers seem to be becoming attuned to.

But what about attention? In today’s fragmented media consumption world it’s hard enough to get the right video ad in front of the right person at the right time. At that crucial moment, the question is “what did the brand hope to achieve?” Hopefully marketers and agencies are being persuaded that focusing on attention metrics like the average time spent forces them to value real people taking a few precious moments with their brand, not just the simplicity of planning to reach and frequency.