âIf youâre a creative person, this is an extraordinary time to be in the opening chapters of quite an extraordinary development platform,â said Mark DâArcy, chief creative officer of Facebookâs Creative Shop, which helps companies tailor their ads to the social network.
Facebook says more than 500 million people watch videos on it every day and viewers have the sound on 50 percent of the time. But the Martin Agency said its data showed that 94 percent of its video ads on Facebook were viewed in silence. Omnicomâs BBDO, which tracks Facebook video views across more than 18 advertising clients, said that on average 82 percent of users watched without sound. Publishers have said the figure is between 82 and 85 percent.
âYou canât elicit the same amount of emotion as when you have sound and visual working together,â said Julian Cole, head of communications planning at BBDO.
Even as such ads have been shortened or created anew for the web, particularly for mobile devices, where Facebook says 75 percent of its video views occur, sound has remained on in apps like YouTube and Snapchat.
âWhen people are watching on YouTube, they have earbuds in and the volume up,â said Kellie Judge, senior vice president of global media partnerships at Amplifi, the central investment division of the ad agency Dentsu Aegis Network.
âWith Facebook and Twitter, people are scrolling a feed with the volume off. The distinction weâve been talking more and more about is not just creating for television versus in-feed, but how itâs so different from other video,â she said.
It is difficult to tell brands they need to tailor their ads for each platform â not to mention pay TV-like dollars to place them there â without proof of their effectiveness, so âFacebook and Twitter are doing a ton of research in that space to combat the advertiser hesitation,â Ms. Judge said.
In the United States, television still commands 72 percent of all video viewing time and television advertising still accounts for about 36 percent of all video-related revenue, according to Activate, a consulting firm for tech and media companies.
âPeople are less willing to sit through an online ad than a 30-second TV commercial,â said Michael J. Wolf, managing director at Activate. âMost online video ads get about six seconds of play before they are skipped.â
While Facebook promoted the âsight, sound and motionâ of its premium video ads in a March 2014 statement, invoking a mantra used by television advertisers for decades, it has since mostly embraced silence. It introduced an auto-captioning feature for video ads in February and instructed brands to âexpress your message visually,â citing an internal study that showed â41 percent of videos were basically meaningless without sound.â
In April, Facebook shared examples from companies like Wells Fargo and Wrigley, and it made recommendations like start âyour video with lifestyle and product shots, recognizable spokespeople, action scenes or a vivid background to spark interest.â
Facebook did confirm last month that it was testing videos that autoplay with sound through some users in Australia, but that it was in the early stages.
Joe Marchese, president of advertising products for the Fox Networks Group, said the lack of sound is a factor that makes it hard to assess the value of online video advertising against traditional TV commercials.
âItâs not that this is not valuable. Itâs just that itâs not the same thing,â Mr. Marchese said. âTV dollars would flood into online if online impressions were the same thing as TV impressions, meaning 100 percent of the screen, the sound very likely on, and all 30 seconds viewed.â
For its part, YouTube said that ad recall was more than three times higher among people exposed to video ads that could be seen and listened to compared with video ads that could only be seen, citing a study of more than 1,400 mobile-ad campaigns.
In June, Snapchat said more than two-thirds of the videos on its platform, including ads, were viewed with sound, which has proved appealing to advertisers even though the platform is much smaller than Facebook and YouTube.
âSound ensures that users are getting the most robust and comprehensive exposure to our film as possible,â said Doug Neil, executive vice president of digital marketing at Universal Pictures.
Imran Khan, Snapchatâs chief strategy officer, went so far as to say that âads that play without sound are more like a moving banner.â
Still, itâs hard to argue with the sheer size of Facebook and how much time people spend there. The company said users spend five times longer looking at video content on Facebook and Instagram compared with unmoving content, including ads.
âThe most important factor is where the consumerâs focus is,â Mr. Wiliams of the Martin Agency said. âYou can have the most epic TV spot that is a visual feast, packed with the best, most well-written voice-over, read by the most famous person, but if youâre not paying attention to it, then it doesnât matter.â