Within 10 seconds you can gain or lose most of the effectiveness of a video

According to a joint study done by Facebook and Nielsen

The effect of just watching a little bit of a video can’t be overlooked. According to the study the people who watched under three seconds of the video ad created up to 47 percent of the total campaign value. The people who watched for fewer than 10 seconds created up to 74 percent, depending on the metric.

One takeaway from this data is that people don’t have to watch a video to be affected by the content. Even video views under 10 seconds effectively build awareness and drive purchase intent.