June 13th, 2008

Metrics: GRPs for the Web?

On MediaPost’s Online Metrics Insider, David Smith argues that the GRPs measured from traditional media (”gross rating points” that measure a percentage of your total audience reached) should be included among web metrics marketers use. He argues they are still a valid measure and help those who still buy a majority of their media offline to make a more direct comparison of web versus traditional buys, he argues.

Commenters to his blog post critique the use of GRPs, partly missing David’s point (helping the client), but make good points of their own — that GRP is flawed and that in its current form cannot connotate an apples-to-apples comparison between traditional media and web-based impressions.

I agree with David that if his clients find GRPs a useful metric, it can’t hurt to use them even with interactive media. I also see many potential problems with doing so from the clients’ standpoint, though, and I would spell out the differences for clients verbally and/or in footnotes if I ever decided to use GRPs for web.

However, there’s never been any GRP in direct marketing and yet marketers still manage to make both media and direct marketing buys intelligently, understanding the difference between the two.

I agree with one commenter it’s kind of hard to compare web and broadcast GRP – certainly not an apples-to-apples comparison for the reason he mentions and because impressions on the web can be video (TV), audio (radio) or web-unique visual (rich media, flash, gif-animated or static that can’t be compared to print), etc.

That’s why another commenter’s idea to try to apply media habits (maybe some kind of weighting tool) to the metric the GRP represents may have some merit — will that be making rocket science of marketing I can’t help but wonder, though!? Don’t forget that metrics are useful, but marketing will always also be part art (not all science) and intuition!