Below is one of the coolest advertising infographics you'll see: the Viral Spiral of most-shared ads from the past five years, built by Unruly Media—the same company that previously brought us the 20 most-shared ads of 2011.
Unruly is interested in the sharing of online video, not just the viewing of it. And the Viral Spiral really illustrates—in a much more powerful, visual way than a set of numbers—just how much video sharing is growing on the Web. For example, look at the Dove "Evolution" spot from 2006 or the Cadbury "Gorilla" spot from 2007. Those were considered viral juggernauts at the time but had just a tiny fraction of the shares of any of 2011's top five.
The other great thing about this infographic is that it lives and breathes. Hovering over any circle brings it to life—and clicking on it opens the full video in a new window. Also, the share numbers are updated three times a day for all videos, going all the way down the spiral. It will be interesting to see whether this growth in sharing continues at quite this pace in 2012.