Excerpt from this article:
Between 75 and 90 percent of Facebook usage in Asia is on mobile (depending on the country) and globally the platform has over 8 billion video views a day. However when these videos start (like on Twitter or Instagram) they autoplay with the sound off. This is a big challenge for advertisers and their agencies. I continue to see brands across the region persisting with putting content made for TV onto social platforms. This typically results in a very poor view rate (which translates back to a very high cost per view) and little to no impact on brand metrics. This is because there isn’t the time to build the story with a captivated audience like there is with TV, or to wait for the ad’s emotional apex, fuelled by the power of a soundtrack, to introduce the brand. News feed environments certainly don’t seem audio-friendly. A recent Digiday interview found up to 85 percent of Facebook video plays without sound. However online video formats can also struggle to deliver audio. Many top publishers have video units that also autoplay without sound, or that are of the click-to-play type (and therefore are often ignored).
No sound, no go? Great video ads have sound, so does that mean I should forget social video? The short answer is no.