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Research Insight | When to Use More Narrators in Your Marketing Video

This study investigates one element of video design that advertisers, entrepreneurs, and marketers can adjust to improve the efficacy of their marketing videos: voiceover narration. Results from large-scale, real-world datasets on crowdfunding and video advertising—using machine learning, text mining, and natural language processing to process and analyze unstructured (multimedia) data—as well as from controlled experiments, provide evidence that voice numerosity can improve consequential crowdfunding project outcomes, perceived advertising efficacy, consumers’ willingness-to-pay for the target product, and consumers’ purchase likelihood. The findings suggest that having multiple narrating voices may be more effective in conveying simpler messages (e.g., about incremental innovation), whereas having one voice may be more effective in conveying more complex product messages (e.g., about disruptive innovations).

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What You Need to Know

  • The persuasive power of a marketing video is enhanced when its spoken narration employs more narrating voices, particularly when conveying simpler messages.
  • Multiple (different) narrating voices can help draw consumers’ attention to the spoken marketing message.
  • The number of narrating voices exerts consistent and economically significant effects on a wide array of consumption behavior.


The authors posit that in an initial exposure to a broadcast video, hearing different voices narrate (in succession) a persuasive message encourages consumers’ attention and processing of the message, thereby facilitating persuasion; this is referred to as the voice numerosity effect. Across four studies (plus validation and replication studies)—including two large-scale, real-world data sets (with more than 11,000 crowdfunding videos and over 3.6 million customer transactions, and more than 1,600 video ads) and two controlled experiments (with over 1,800 participants)—the results provide support for the hypothesized effect. The effect (1) has consequential, economic implications in a real-world marketplace, (2) is more pronounced when the message is easier to comprehend, (3) is more pronounced when consumers have the capacity to process the ad message, and (4) is mediated by the favorability of consumers’ cognitive responses. The authors demonstrate the use of machine learning, text mining, and natural language processing to process and analyze unstructured (multimedia) data. Theoretical and marketing implications are discussed.

Hannah H. Chang, Anirban Mukherjee, and Amitava Chattopadhyay, “More Voices Persuade: The Attentional Benefits of Voice Numerosity,” Journal of Marketing Research, forthcoming. doi:10.1177/00222437221134115