When meeting with a new client, one of the first questions we'll usually ask during the fact-finding process is "Have you thought about duration?" Or, conversely, the client will open the conversation with, "I'm looking for a 30-minute video." It's funny, for some reason "30 minutes" seems to be standard lingo for "longer than a commercial."
Truth is, 30 minutes can be a very long time. Lots of folks don't realize that - even an average half-hour sitcom is only 22 minutes long. Shorter is better. Most viewers have an attention span of approximately eight minutes. Anything longer, and unless your content is truly compelling, chances are you'll lose them. With the increased presence of web-based, online video, the need to keep things brief is more crucial than ever
You may or may not be a member of your own target audience, but when you're planning your next video project, it can't hurt to think about what you'd be willing to watch in order to gain information or look at a new product.
Here's a trick: when you think you've given up all the information you have to give, pull back and start cutting. Always keep your viewers wanting more, and you'll almost guarantee yourself an audience.