This is a really important question for any business considering using online video... Just how long should a video on your website be? 30 seconds, 2 minutes, 10 minutes… an hour?
I did a little hunting around on the Internet for some research into this and came across some fantastic work done by a professional video hosting company called Wistia in the US.
If you’re interested you can check out their full blog article here but I’ll try sum up the important things to take away and maybe add some of my own musings in there as well…
With videos of all lengths there is a consistent viewer drop off pattern that when graphed shows a steep drop near the beginning of the video followed by a flattening off to a slow, steady drop off rate through the middle, and finally a sharp drop off again near the end (presumably as people realise the video is wrapping up and it’s ok to stop watching).
As shown in the graph though, videos of different lengths observed vastly different drop of rates at the beginning of the video, which suggests that people understandably take into consideration the time commitment required when deciding whether to keep watching. The longer the video the higher the drop off rate at the start, which leads to the conclusion that in general...
SHORTER IS BETTER... If you can get your message or content across in a more succinct video, then do so. 30 seconds however isn’t a lot of time and if the message will be compromised at all by reducing it to a 30 second sound bite then I would still recommend taking the time needed. Just keep in mind that the longer the video the more time commitment required by the viewer and therefore the greater the chance that you'll loose your viewer before the end.
A good way to tackle the problem of having too much content to get across in a video is to break a longer video down into several shorter ones. This helps the viewer organise the information in their head and to stay engaged with each topic.
Considering also the other steep drop off in the graph that happens right at the end when a video is wrapping up suggests that putting anything important right at the end (a call to action slide or your web address for example) is likely to be missed by a large number of viewers. To avoid this happening you could either incorporate this important information earlier in the video or possibly bring the video to something of an abrupt end so that viewers don't stop watching too early.
Another really interesting point that the guys at Wistia discovered is shown in this graph above where you can see that the most dramatic drop in average percentage watched can be seen in the difference between the very short videos (0-30sec, 30sec-1min, 1-2min) and again between the very long videos (10-20min, 20-30min, 30-45min). So although the average percentage viewed for videos in the middle there (between 2-3min and 5-10min) is still dropping, the difference really isn't all that great.
What all this suggests is that if your video is engaging enough to get the viewer interested in the first minute or so then most people will stick around and watch to the end as long as it doesn't require a commitment of longer than roughly 10 minutes. So if for example if you have an engaging longer form video that feels well paced at 7 minutes in length then there is probably nothing to be gained from cutting it down.
The other really important factor to add in here at this point is to consider video length from the point of view of your target audience. Ask yourself "If I was this person how much time would I happily give to watching this?" For a landing page promotional video where there is a lot of competition out there on the web and many different companies that the viewer will be wanting to check out before making a decision, you may really only have 30-60 seconds to catch the viewer's attention.
Something like a recruiting video however with a target audience of potential employees trying decide if they want to apply to work for your company will be much more willing to spend 5-10 minutes to find out about working there. Likewise with online training and content marketing videos, if you're focus is on training or solving one of the viewer's problems, then you can be confident that if it's engaging and well paced then the viewer will be more than happy to give you an appropriate amount of time.