We've crunched the numbers and have found that videos perform best when they are 10-17 seconds long.
This doesn't mean that every video should follow this rule. Not every content creator will be able to share their message in this amount of time.
Do your best to grab the audiences attention quickly. If you can tell a story, make someone laugh, or teach someone something new in 10-17 seconds, your video will have the opportunity to succeed.