While YouTube and Facebook have established themselves as major hubs for mobile video, the lifespan of content on each platform is markedly different. Put in astronomical terms, a Facebook video is a brief supernova, peaking early and then quickly fading out; a YouTube video is more like a cooling star that emits a small flash of light then slowly decays.

Videos posted on Facebook draw more than 75% of their views within four days, peaking on the second day, according to analysis of around 1,700 videos done by ChannelMeter, an analytics service. The same videos on YouTube took 79 days to reach the same proportion of their audience (see accompanying chart). The videos analyzed by ChannelMeter were posted in the last year.