GLOBAL: Fifteen-second commercials may be as effective, both rationally and emotionally, as traditional 30-second ones when it comes to brand building, according to new research which challenges received wisdom on how long an ad should be.

Writing in the current issue of Admap, Michael Sankey and Ken Roberts, principal consultant and founder respectively, at Forethought, outline how they looked beyond the usual ad metrics of liking, awareness and recall in an examination of ad length.

“The measures used to assess consumer response to communication have little relevance as drivers of consumers' choice, and therefore no resultant impact on commercial outcomes such as driving market share,” they note.

Accordingly they devised a framework to measure quantitatively verified rational drivers and discrete emotions underpinning consumption behaviour, assessing the relative impact of 15- vs. 30-second advertisements for well-known brands across various product and service categories.

The authors report “non-significant differences in rational and emotional performance”.

They posit that this can be explained by the peak-end rule, suggesting that consumers evaluate advertising communications by moments and that duration is not a factor in this process.

“For commercials with similar creative elements (notably, a consistent peak and end scene), duration had little impact on effectiveness,” they state.

Creatives will therefore have to think carefully about how they structure a commercial – “a valley is required to establish a peak” – and consider that positive peak and end moments may not actually be suitable for brands in some categories.

While there are clearly potential cost benefits for advertisers if they are able to achieve the same results in half the time, the authors take care to point out “It is not our contention that 15-second advertisements be universally preferred over 30-second ads”.

Strategy will rather be based on each brand’s unique situation. “Those seeking to build brands should consider investing in at least some longer-form spots,” they suggest.

Longer commercials not only have a greater opportunity to elicit emotion, they are also more appropriate when communicating complex messages such as launching a new product or campaign.

But in the current advertising landscape, if brands fully understand the primary rational messages and discrete emotions driving consumer behaviour in their category, then “15 seconds is plenty of time to effectively disseminate them to your target audience”.

Sourced from Admap