This is a question that I get asked a lot. It might be tempting to reply ‘How long is a piece of string?’ but actually there is an answer for website video, which is, ‘Keep it short!’
Before I go any further there are exceptions to this. If you are making a HowTo video, or a video tutorial, which people will seek out to get information, then you can make the video as long as it needs to be.
The difference is when viewing your video is discretionary. They’ve arrived at your page looking for a service and if they click on your video they will learn more. However they have other sites to go and look at, so they don’t want to waste too much time. I’ve come to the conclusion that 2 minutes is the maximum website video duration and psychologically it makes a huge difference if it’s 1’59” rather than 2’00” ! Looking at this image, 1′ 41″ doesn’t seem like it’ll take up too much of your day.
But what if you have a really interesting interview with someone who has lots to say? I suggest that you can split the video up into shorter clips, each dealing with a different subject area. This also lets people choose the information that they want to see. You might lose someone who doesn’t want to sit through things they already know, and you don’t want them leaving that page. My own showreel is only 1’03”; I’m planning that you’ll watch it all the way through…