It has long been said that the unique strength and advantage of PR is that it is much more credible as an information source than advertising.
Over the years, this belief has become entrenched in PR "lore" as a "multiplier" effect where the value of a PR placement is between three and six times the equivalent value of a comparable advertisement.
Three years ago, we started wondering about the existence of this multiplier. After an exhaustive literature review, we found little, if any, evidence supporting its existence. What research that did exist was pretty much non-experimental and failed to meet the stringent conditions required for causality.
The question we asked ourselves was whether there truly is a multiplier effect, and, if it does exist, how much is it. Hence, we decided to test for the effect using the strictest social science research methods.
What we did and found (or failed to find, depending on your point of view) has been controversial and has provoked much discussion when we formally presented our findings. After conducting two experiments on two different populations, we failed to find the existence of a multiplier.
Our most recent study was based on a product introduction for a new brand of snack chip. We developed a print ad and print editorial that had matched copy points, and we sampled a large number of newspaper readers (351) in six malls across the US.
The study participants were randomly placed into experimental or control groups. We used multiple measures (awareness of the brand, knowledge about the brand, relevance of the brand to the participant, intent to purchase, and product credibility and homophyly), and we tested the items for statistical reliability and validity.
We found both the editorial and the ad equally effective in promoting the product, but no statistically significant differences existed between the two across measures of awareness, information, intent to purchase, and product credibility.
We did find one significant difference - those reading the editorial saw the product more closely related to their lifestyles than those reading the advertising - but we failed to find a multiplier effect. This occurred even though we had the perfect, positive editorial review of our product.
So what are the lessons here? First, while a multiplier may exist in some circumstances, it is not universal and does not exist across all PR activities. Second, the number of exposures, the editorial tone, the ability to control the message, and the context of the communications may influence the multiplier effect. Third, although we hear of multipliers ranging up to six times advertising, if they do exist, they are probably lower and will vary significantly by context, environment, and practice.
So, are these findings positive or negative? Our view is that we have demonstrated equality with advertising, hence PR should be afforded the same support and financing as advertising. It should include an adequate research budget to "prove" impact or ROI.
Rather than being defensive, we would argue that the preliminary findings offer support to go on the offensive... to proactively state PR's position in the marketing mix at the least and, with more study, probably demonstrate increased effectiveness as we better understand how the multiplier works, if it truly exists.
Dr. Don Stacks is program director and professor of PR at the University of Miami. Dr. David Michaelson is principal at David Michaelson & Co.