Zarrella's Hierarchy of Contagiousness
Book Review: Zarrella’s Hiearchy of Contagiousness: The Science, Design, and Engineering of Contagious Ideas by Dan Zarrella

I like Dan Zarrella’s approach to social media. Amidst a horde of social media gurus, experts, mavens, and missionaries, Zarrella relies on crunching numbers to create his insights. Instead of thinking up “10 Ways to Get Retweets,” he analyzes millions of actual retweets to find out what works. (Oddly, putting “please RT” in your tweet actually does work.) Hierarchy is a bite-size book from Domino. With the same small form factor as Seth Godin’s Poke the Box, this book can be read in an hour. The length may be an advantage. Zarrella could no doubt have filled hundreds of pages with data and insights from his social media research. Instead, he presents a modest number of concepts that are readily digested and implemented.

Hierarchy, in simple terms, explains why people share content and what content gets shared the most. For businesses who use social media to reach new customers, this is the crux of social promotion. Why do fifty tweets vanish from the radar in minutes, while one lives on for many hours with hundreds of shares? Zarrella may not provide a magic formula to make every tweet golden, but his insights will help increase the probability that your content will get shared.

A few of the questions Zarrella answers with his detailed statistical analysis:

  • When should I post to my blog for maximum link generation? 6AM to 8AM is most productive.
  • What if I’m hoping for comments on my blog post? Post on Saturday or Sunday for maximum reader interaction.
  • When should I send an email for best clickthrough rates? Surprisingly, emails sent on Saturday or Sunday had higher click rates, while emails sent on Monday, Tuesday, and Wednesday (the “prime” email days according to many experts) had the highest unsubscribe rates.

Hierarchy is full of nuggets like those, all based on hard numbers generated with sample sizes that range from big to ginormous.

Kindle Pricing

Domino, Seth Godin’s publishing venture that is responsible for Hierarchy, is following its unconventional pricing path with Zarrella’s book. While the hardcover version is priced fairly normally at $9.99, the Kindle version is currently just $1.99, and readable for free for Amazon Prime members. (Note, these are U.S. prices at time of writing this post – international prices will vary, and I presume even the U.S. pricing strategy could change.) This kind of aggressive ebook pricing really skews the sales ratio. While the hardcover isn’t currently very visible on Amazon’s top lists, the ebook is a bestseller.

Up Your Slugging Percentage

Think of Zarrella’s advice like that of a batting coach. A batting coach may be able to change a rookie in the minor leagues from a strikeout king to a respectable hitter. And even though major league batters are usually pretty good by the time they reach that level, if a coach can improve their technique even a little it can have a big impact over an entire season. Even the best batters get on base only a fraction of the time. Zarrella’s advice won’t make every piece of content you share go viral, but if you listen to him you’ll strike out less often.

Kindle Ebook: Zarrella’s Hierarchy of Contagiousness: The Science, Design, and Engineering of Contagious Ideas

Amazon Hardcover: Zarrella’s Hierarchy of Contagiousness: The Science, Design, and Engineering of Contagious Ideas