Black Holes and YouTube attention span

This video about Black Holes has become the first Sixty Symbols video to be watched 100,000 times.

It reached the milestone just ahead of our video about the drinking bird (97,000 at time of writing)....

But this brings me to my observation on the black holes video.

Because people have short attention spans, I often try to put the best material near the start of a video, otherwise viewers may never see it.

That's especially true for a video as long as this one about black holes, which weighs in at a whopping 6 minutes and 37 seconds.....

However YouTube viewer comments show the part of this video which intrigues many people comes near the end.

From about the five-minute mark Omar Almaini (the astronomer in the film) reveals images from the centre of the Milky Way, and "proof" of the enormous black hole which lives there!

YouTube "hotspot" data backs up the anecdotal evidence that this section of the video is popular

Here is the graph for the black holes video:

And here is YouTube's explanation of what the graph means...

"The ups-and-downs of viewership at each moment in your video, compared to videos of similar length. The higher the graph, the hotter your video: fewer viewers are leaving your video and they may also be rewinding to watch that point in the video again. Audience attention is an overall measure of your video's ability to retain its audience."