Zarrella’s Hierarchy of Contagiousness – A review


A few days ago I bought and downloaded the ubiquitous eBook Zarrella’s Hierarchy of Contagiousness: The Science, Design, and Engineering of Contagious Ideas. There is a lot of stuff about social media out there but I find that many materials are fuzzy and hype-oriented. Dan Zarrella’s book is definitely different and I think that Business Analytics professionals like you will enjoy the book.


Social media have changed the way we market to our customers. But reaching the right people is not all that easy as you have probably experienced. The basic idea of Zarrella’s book is to look at why certain ideas are contagious and what you can do to make sure that your message is heard in the various social media channels. Zarrella introduces a useful model (Zarrella’s Hierarchy) that helps explain how messages get spread through social media. It is a hierarchy of three criteria:

  1. Exposure: People need to be exposed to a piece of content.
  2. Attention: Once people are exposed, will they actually notice the message?
  3. Motivation: Once an idea has been noticed, will people share it with others?


Zarrella's Hierarchy
Zarrella's Hierarchy reads well on the Kindle


The author then works through the three criteria to show how you can make sure your messages are being heard and shared by others. And this is where the book gets exciting. While many social media books rely on anecdotal evidence and outrageous ‘success stories’, Zarrella leverages data to show you how to be more successful.

“If you’ve read about social media or been to any marketing conferences, you’ve probably heard tons of advice like “love your customers,” “engage in the conversation,” “be yourself,” and “make friends.” I call this “unicorns-and-rainbows advice.” Sure, it sounds good and it probably makes you feel all warm and fuzzy. But it’s not actually based on anything more substantial than “truthiness” and guesswork.”  — Dan Zarrella

Zarrella uses data he has collected over the years to show practical things like:

  • When to tweet your valuable content so that it gets retweeted
  • What is the best time to post new and fresh blog content
  • Does it make sense to talk about yourself
  • What type of words and phrases typically catch attention

Every piece of advice is backed up by data. And that is pretty cool. Along the way, Zarrella also encourages the reader to collect and analyze data as well.


 Zarrella’s Hierarchy of Contagiousness is a great but very quick read. His hierarchy model is very useful and there are certainly a number of interesting ideas and tips in the book. For me, the most interesting aspect of the book is the use of data to show how and why social media can help you promote your content. While reading the book I often turned to Google Analytics, Twitter and Facebook to test a few assumptions myself. The only negative thing I can say about the book is the price: USD 7.99 for the eBook is a bit steep for 60 pages. If you are looking for a book that shows you how to develop those great and sticky ideas, I highly recommend Made to Stick: Why Some Ideas Survive and Others Die by Dan and Chip Heath.

Recommendation: 4 stars out of 5

P.S.: Collecting and analyzing social media shouldn’t be a manual task. It is a lot easier with Cognos Consumer Insight….. 🙂

“When I first started down the path of science and I began to see beyond the myths, I was angry. I felt lied to by the marketing idols I had looked up to.” — Dan Zarrella


2 responses to “Zarrella’s Hierarchy of Contagiousness – A review”

  1. Holly Rice

    I follow Dan Zarrella and receive his emails! Glad you posted about this!

  2. I think it’s definitely important to know when to tweet and post blogs, they can have a massive impact on how many people share and view your content. Why go to the trouble of writing a great post if no one will see it…