Short videos get better completions rates in the Facebook newsfeed, according to a blog post from Social Bakers, published August 8, 2014.
This seems an intuitive, if not obvious point, if you’ve ever watched someone frantically scroll or swipe through the Facebook newsfeed to find the latest juicy story about “10 Ways You’re Using Facebook All Wrong and Why it Will Probably Cause You to Make 12 Mistakes in your 20s or 17 Mistakes in your 30s”.
To quote the blog post:
For this study, we chose to use completion as our measuring stick – Facebook provides robust metrics around video completion rates, so this makes it a thorough metric for our purposes, and most accurate. We found that videos that were less than ~21 seconds performed in the Top 25% for completion rates.
So there you have it. Make all of your videos less than 21 seconds if you want most people in most situations to watch them to completion.
The full story is more complex, of course. The purpose of a video is extremely important to determining its content and its length. Some of the most successful online videos of all time – at least in terms of views – have been far longer than 20 seconds.
So, how long should video ads be? If you can make a video that fully conveys your message and can entice people to take your call-to-action within 20 seconds, go for it. Short videos can be great and at Shakr we have a large number of videos that pack a lot of message into 15 to 20 seconds.
That said, don’t place an arbitrary limit on your videos. If you need some extra seconds to make your point, use them. After all, the people who stick around to watch your full video are a self-selecting bunch, and you know they’re interested.