As many readers of this blog know, I often expose my inner media geek. Since leaving the agency world two years ago, I’ve had the opportunity to share all of the secret digital media sauce amassed throughout a carreer at the healm of an innovative, nimble and successful digital agency.
I now spend my time consulting other agencies and marketers, and presenting digital media planning & buying, and social media marketing training seminars around the country as part of my role at Laredo Group. In today’s edition of the Laredo Group newsletter, I authored an article about the role of GRP’s in digital media planning, and decided that it is too important a topic not to share with you. Would love to hear your thoughts and comments! Enjoy…
To GRP or Not to GRP?
Few topics evoke such passionate debate among senior level media strategists as “the role of the GRP/TRP metric online”. For the purpose of this article, each generic reference to GRP is in actuality a TRP reference, as is the case in most media conversations.
Since the dawn of media planning time, media impact has been predicted and evaluated as a function of the relationship of reach and frequency against a defined target universe – essentially the percentage reach against a target multiplied by the frequency:
- GRP = (Reach/Target Universe x 100) x Frequency
Generally, the Nielsen television universe is used as the denominator in the reach calculation due to its close representation of the actual universe of US households. Proponents of a related metric, the iGRP, use the online universe of the target as the denominator of the calculation.
Allow me to lay out the arguments of both sides…
The argument for using GRP’s goes something like this: Advertisers use GRP’s to measure traditional media, so why should online be any different? Having an apples-to-apples metric allows advertisers to evaluate all media uniformly and in a more integrated fashion as part of a mix.
The argument against GRP’s: We shouldn’t fit a square peg of new media dynamics into the round hole of a traditional media planning model. The GRP doesn’t account for the unique attributes of digital media, such as engagement and relevant targeting. “Apples-to-apples” comparisons are rare because online targets are more psychographically defined, while traditional GRP evaluations only incorporate demographics. The iGRP further muddies the proverbial waters by using a different universe than the traditional GRP altogether, thereby countering the primary argument that the GRP provides an apples-to-apples comparison across media.
Whether you are for or against the use of GRP’s, nobody will argue against the importance of understanding how reach and frequency affect campaign impact.
There are plenty of ways to measure this influence and develop media mix models without retrofitting the GRP.
While the argument focuses around the GRP, the real issue quite simply stems from a difference in media currency, not evaluation metrics. While the unit of media currency for both traditional and digital media is called the “impression”, the underlying currencies are different. The currency of traditional media is “audience”, where impressions equal reach. However, digital media impressions are equal to reach x frequency. As a result there is an over abundance of devalued online ad inventory. Just think about the impact of the value of $1 if the government just flooded the market with newly minted currency.
As an example of these currency differences – if you buy a spot during a TV program that reaches 1MM viewers, you are buying 1MM impressions, and reach equals 1MM. Frequency is a function of additional buys. When you buy 1MM impressions from a particular website, you buy a share of voice, not the total audience. In this instance, your 1MM impressions can yield 1MM people at a frequency of 1, or 50,000 people at a frequency of 20. In either case your GRP’s would not give you the ability to judge the relationship of reach and frequency of your buy – a frequency cap would.
The Final Word –
With all the breadth of data and analytic tools available, why focus on a metric that aims to predict impact, when impact and influence can be measured? Make sure that all buys have frequency cap parameters so that you can predict reach and frequency, then measure the metrics that matter based on your objectives. Online, you can actually measure the frequency at which you hit a point of diminishing returns on branding effectiveness, or the frequency at which you achieve your best direct response performance. After all, isn’t media impact what the GRP tries to predict in the first place?
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