- 2008年6月18日

Do GRPs Have a Place in Online Media?

Josh Chasin
Josh Chasin
Chief Research Officer

It's funny how things stay with you.

In the fall of 1980, as a second-half senior at NYU, I was taking a class called Advertising and Media Planning. I'd already begun working part-time at Arbitron, so I thought I knew a thing or two. On the midterm, one of the questions was: "Define Gross Rating Points." I confidently answered: "reach times frequency." But the professor was looking for the textbook answer — "the sum of the ratings achieved by a media schedule" — and my answer was marked wrong. I went to his office and argued, but nothing I could tell him would convince him that, indeed, GRPs are the product of reach and frequenc

I was a cocky kid with big dreams, dreams of one day becoming Chief Research Officer at an Internet Metrics company, so you can imagine how this episode scarred me. If that professor is reading this, then let me assert with all the authority and gravitas of my position at Comscore, and as a Media Post columnist: GRPs are the product of Reach and Frequency.

Last week, David Smith argued for the efficacy of GRPs as an Internet advertising metric, and a lively debate ensued in the comment section. The case for online GRPs goes something like this: GRPs put online advertising on equal footing with traditional advertising, thus supporting the migration to, and integration of, online advertising as part of the media mix for more categories, brands and advertisers.

The argument against: GRPs are important to traditional media because those poor slobs have nothing else to measure, but here in the digital age, we can measure clicks per you-name-it, rendering GRPs hopelessly archaic. Besides, why settle for equal footing when our metrics make us better than equal?

Perhaps because of my traumatic experience in college, I find myself in the former camp.

Of course, framing the question as either/or is a false premise.

GRPs can and do co-exist with other, more interactive metrics. In fact, I would even suggest that GRPs are a valuable metric for CPA campaigns — because if I know that a certain creative execution is generating actions against a specific target population, I'd like to know: (1) What percent of that target was exposed to the campaign? (maybe I will get more activities by putting it in front of more of that target); and (2) What is the optimal number of exposures to my campaign to elicit that action? (Online advertisers care about this, hence frequency capping.) Can I better manage my CPA campaign if I track these metrics? If yes, well, those metrics are reach and frequency, and if I multiply them together, despite what my NYU professor thought, I'll get GRPs. (I should add that even a behavioral target is, indeed, a target.)

There is one other argument against online GRPs that I'd like to dispel: that somehow the Internet doesn't lend itself to GRPs, at least not as readily as TV or print. I know this to be false, because at Comscore, we offer a reach/frequency tool as part of our client interface, and about 100 interactive agencies regularly use this tool to plan campaigns for their clients — running, combined, over 20,000 campaigns a month.

Very specifically, this tool allows users to build campaign schedules by allocating numbers of impressions against a target demographic on different sites, and then showing the aggregate, unduplicated reach (and average frequency) of those impressions across sites.

If an advertiser wants to use online advertising to get a message in front of women 21-49 with kids, and to reach 70% of them at least three times, the tools exist to enable that. I can't think of a single good reason to discourage the practice. Indeed, the entire digital space should be encouraging the practice, because that is the way an awful lot of ad dollars are spent today. The state of the economy is such that competition across media for ad dollars will be increasingly fierce. Making Internet advertising more user-friendly for the people looking to spend heavily to get a message in front of a target audience — that's a no-brainer. The GRP metric and its component parts does nothing but help.

David Smith noted: "We do not generally have easily accessible reach and frequency data for the Web." I think I know what he means — campaigns are ultimately priced based on served impressions, and while we may be able to create pre-buy campaign metrics as readily as in other media, post-buy evaluation is still held to rely on reporting by third party ad servers; thus, it's prone to all the limitations implied by cookie-based tracking.

I want to point out that many advertisers are already using tools, such as Comscore's Ad Metrix, which integrates audience measurement data with ad occurrence data to provide post hoc campaign-level reach and frequency.

I don't think there are obstacles preventing advertisers and agencies from planning online media campaigns based on reach, frequency and GRPs, should they be so inclined. Nor should publishers be discouraged from selling inventory that way, as long as there is a market voracious for cost-efficient, targeted brand advertising.