It almost goes without saying that there’s no “one size fits all” answer which applies to every company or corporate video, either offline or online. However, we can work out 'how to work out' an effective length.

The ideal length (or ‘runtime’) depends on a huge number of different factors. The more factors you know, the more you can start to determine how long people are likely to stick around to watch your video. If the video is too short, the viewer may be left “hanging” – wanting more information or detail. They may feel cheated, or that the video (and therefore – your business) is not delivering what was promised.

If it’s too long, the bored viewer will simply stop watching, or click away if online. They may even feel frustration or worse, that you’ve wasted their time and have still not delivered anything of value to them. Frustrating potential customers is definitely not good business sense! Video is immensely powerful – but only if it gets watched. Video which doesn’t get watched is pointless.

Businesses which spend money on video which doesn’t get watched are throwing money down the drain.

David Lean’s epic ‘Lawrence Of Arabia’ runs for for 3 hours 36 minutes and many would say it doesn’t feel too long, thanks to the acting, directing and story. However 2016’s movie ‘Paint Drying’ (yes, it's a real movie!) is unlikely to hold viewer’s attention for all of it’s 10 hour run time.

So there’s the single most important factor – the right length of video is entirely subjective. It’s opinion. Having said that, here the major factors which influence the viewer’s opinion and utlimately, that's the only opinion which matters.

Type of Video

Is it an advert? A Corporate Promo film? Does the video need to explain a process? Is it funny, informative, viral or educational?

An Advert video which is designed to interrupt a viewer and persuade them to take some sort of action (eg. Buy a product, sign up for something) usually needs to be as short as possible. You’ll probably have noticed on Youtube, that pre-play ads shown before “actual content” are cleverly designed to have the important phrases and ad content up front – in the first 2 or 3 seconds. That’s how little time you have to grab someone’s attention if you’re interrupting them.

An explainer video or animation designed to show how a widget works needs to do so in as short a time as possible – but not cut any corners to do so, otherwise you risk confusing the viewer or simply failing to explain what you wanted to.

A training video viewed by someone who is interested in learning what the video delivers, can be significantly longer – 10, 30 minutes, even an hour or more.

Facebook timeline advert videos are also “interruptions” to the viewer’s chain of thought (which is focussed on their timeline). Many viewers will watch the first 15 seconds, but significantly fewer will see the second 15 seconds. A fraction of them will see the third 15 seconds.

Placement

Where is the video being shown? Even within the limited context of a website, video is viewed differently. A homepage video is likely being seen by a cold audience with a shorter attention span so the video should be shorter, maybe 60 seconds or less.

A product video on a sales page is being viewed by someone who is already interested in that product. The video can take a little more time to go in to detail, maybe 90 seconds or more.

Audience

Who do you expect will watch your video, how old are they, what are they interested in and what are they doing when they see your video?

If your target audience is a manager, sat at a computer in an office during the day, they may spend 2 minutes watching detail about your company.

If “busy mum” catches your video at 7pm, she might see no more than 2 seconds. However – she may listen to more as her attention is distracted, then watch again when she has chance.

As a general rule-of-thumb:

• 33% of viewers stop watching after 30 seconds.
• 50% have stopped watching by 60 seconds.
• After 2 minutes, nearly 75% of viewers have stopped watching.
• 95% of rules-of-thumb are way too general to be terribly helpful.

Obviously these numbers vary hugely according to target audience, purpose, placement and so on. Mobile viewing statistics are much harsher, but all these numbers are further complicated by the fact that 2 of the major places to view video, Youtube and Facebook, measure what counts as a “view” or a “partial view” differently. We can say with certainty that:

Any video (especially corporate or business videos) must be no longer than it takes to have the desired effect on the viewer.

An increasingly important way of fine tuning this balancing act for online video is by looking at analytics from the likes of Facebook and Google. It’s possible to see exactly how much of a video gets watched, and what viewers do at different stages along the way.

Tweaking and editing video for maximum effect based upon this feedback can make a massive difference to the return it delivers on your investment of making it.