Back to Blog


How long should it be?

By Marketforce
April, 2018

It’s a question we get asked often: How long should it be? How long is long enough? Does length really matter? After a wry smile, it’s actually an easy question to answer…

An examination of ad length: 15 vs. 30 secs by Michael Sankey and Ken Roberts (Source: Admap, March 2018) provides the most up-to-date testing on video length effectiveness. Using rational and emotional drivers of brand choice, this article examines research into the relative performance of 15-sec and 30-sec ads. But the same learnings can be applied to 6 sec You Tube pre-rolls, 2 minute video vignettes, or as was the case for me recently, a 41 second promotional video.

Traditional practice and logic prescribes that longer ads are necessary to deliver a meaningful impression, complex ideas and evoke an emotional response. However, social media, mobile and new digital formats has led to shorter attention spans among viewers. YouTube, Twitter and Facebook are heavily promoting six second ads. On TV, the currency for decades has been 15-, 30- and 60-second ads. These formats continue to have a large presence on digital platforms despite the move towards short-form video. But Fox Television is aiming to make the six second format an industry broadcast standard in the US.

The new research by Sankey and Roberts confirms the current evidence: 15- and 30-second ads were at parity in terms of their rational, emotional and overall ad performance. It found that 15-second ads were 80% as effective in achieving ad recall and 90% as likeable as 30-second commercials.

So, it really doesn’t matter how long your video content is, as long as the video is compelling and well-constructed. Easy, right?!

The psychological heuristic, or short-cut, the peak–end rule helps structure video storytelling. Viewers evaluate communications by moments. Rather than evaluating all information at once, viewers will extract a ‘representative moment’ and use the assessment of this moment to evaluate the complete piece. This rule suggests only two moments are important: the peak – the most positive experience during a communication; and the end – the more positive the end, the better the overall experience.

The very practical insight for marketers is clear: structure creative storytelling to have strong peak and end moments. For commercials with similar creative elements (notably, a consistent peak and end scene), length had little impact on effectiveness.

Importantly, when designing the long and short videos, marketers should aim to incorporate the same peak and end moments in both executions.

So length really doesn’t matter. It’s the quality of the creative content that counts!