7 Viral Marketing Lessons Learned from The Swine Flu Virus

The name viral marketing stems from the theory that ideas spread like viruses, making epidemiological metaphors and models useful when attempting to understand the spread of memes. Since the goal of any viral marketer is to create a pandemic with their campaign, we can learn a lot from the early spread of Swine Flu. Here are 7 valuable lessons to take away from this virus.

1 Seed Selection

First emerging near the very densely populated Mexico City, Swine Flu seemed to travel to half a dozen other countries around the world over night. Many of the first confirmed cases were among children in schools who had taken trips to the popular Mexican vacation destination.

Children, due to their gregarious nature and low levels of hygiene awareness, are called the “super spreaders” of this outbreak, prompting many schools to close. Children are often blamed for a host of illnesses, but perhaps the most famous super spreader was Typhoid Mary, a cook who was responsible for 2 outbreaks of typhoid fever in the early part of the 1900s.

When planning to seed a viral marketing campaign it is important to take into account which members of the target audience have the most potential to be contagious. Typically, savvy social media users, including bloggers, Twitter users, Diggers and Facebook fanatics, are the best seeds.

2 Knowledge Gaps

A phenomenon I first noticed when reading a World War II era research paper by the CIA-precursor, the OSS, discusses the spreading of information when knowledge about a particular topic is scarce.

The OSS paper says that good rumors are “provoked by” and provide interpretation or elaboration on a current event, filling a “knowledge gap.” If the locals heard a big boom earlier in the day, a rumor could easily be constructed to explain it if the authorities did not.

In the absence of official or authoritative information, rumors proliferate. The CDC has actually been pretty good at communicating authoritative information about Swine Flu, but in those pockets where people are unaware of it, lots of “theories” and “facts” have emerged. For example, some countries have banned imports of pork products, despite the fact that meat cannot carry the Swine Flu virus, h2N1.

3 Addition vs Replacement

Because the common name “Swine Flu” misrepresents the origin and dangers of the virus (and does not conform to historic convention of naming influenza outbreaks for the geographic region they first emerged from), several organizations have tried to “rename” it, but none have taken hold in the public discourse.

Each of us has a mental framework of ideas built on each other that we use to view and understand the world around us. When we are exposed to a new meme that contradicts an existing portion of our framework, it is very difficult for the new idea to replace the old idea. It is much easier for us to assimilate new ideas that either agree with or expand on our existing mental frameworks. Think of an under-construction brick house: it takes much more effort to replace a previously laid brick with a new one than it does to begin building an addition onto the house with the new bricks.

4 Novelty

One of the factors that makes this version of the swine flu so dangerous is that it is a novel combination of several genetic sources for which humans have built up no natural immunity and for which no vaccines exist. The 2009 version of the h2N1 virus is essentially a remix of previously existing strains and may form the bridge by which the most virulent forms of human, bird and swine flus can merge and co-evolve.

In the study of applied memetics, we learn that one of the requirements for a successful meme is that it possess some form of novelty. It is often easiest to achieve easily understood novelty by putting new content in an old structure, or putting old content in a new structure.

5 Communal Recreation

Viruses evolve like a giant game of “telephone,” as each host that becomes infected with a particular strain offers the pathogen a chance to evolve into a new variety. This means that the Swine Flu is rapidly morphing and multiple strains probably already exist. The higher mortality rate in Mexico may be due to a more deadly version having evolved there that hasn’t yet spread abroad.

In urban legends, rumors, slang and many other forms of social communication, each person who is exposed to a particular meme creates their own version of it before passing it on, often fitting it to their personal and societal frameworks, thereby making it more adept at spreading in their community. Therefore, successful campaigns must allow and encourage remixing by their target audiences.

6 Infectious Period Length

The period of time from infection to non-contagiousness of a pathogen is known as it’s “infectious period.” This is when the person is a potential seed for the virus. The CDC has defined Swine Flu’s infection period as:

Infectious period for a confirmed case of swine influenza A (h2N1) virus infection is defined as 1 day prior to the case’s illness onset to 7 days after onset.

The longer the infectious period lasts, the more secondary cases may result from an un-quarantined primary case.

In the case of most viral and social marketing campaigns, the infectious period exists as an event rather than a period of time. An “infected” person will blog or Tweet about something. The goal for viral marketers looking to exploit the infectious period should then be to increase the number of infectious events each individual will undertake.

7 Endemic vs Epidemic

In mathematical models of epidemiology, there are 2 concepts of the “state” of the spread of a “successful” pathogen: endemic steady state and epidemic. Assuming a population with zero immunity (because this outbreak is a novel h2N1 strain, no one has any natural immunity to it yet), an endemic state indicates that each infected person infects exactly 1 other person; an epidemic state indicates that each case will cause multiple cases. The steady state means that the outbreak will continue to spread without external influences. Viruses that enter the epidemic state will eventually either die out due to exponential growth or reach the endemic steady state.

In viral marketing, we must strive to understand and improve the reproduction rate of our campaigns. We can assume zero immunity because, except in certain rare cases, people aren’t immune to most ideas. With social marketing, however, we tend to see a reproduction rate of far under 1, that is each “infected” person will infect less than 1 person on average. This has lead to research into extending the total reach of a meme through “big seeding,” but when you model total campaign spread as a function of seed size and reproduction rate, it is much more effective to increase the reproduction rate. As marketers, it is crucial to encourage each user to spread the campaign to as many other users as possible, rather than try to “seed” it with huge numbers of initial users.

If you liked this post, don't forget to subscribe to my RSS feed or my email newsletter so you never miss the science.


Mark Evertz April 30, 2009 at 5:00 pm

Absolutely fascinating, logical, topical and inspirational. Thank you Swine Flu! You’ve made me a better marketer.
Seriously…way to weave a good story.

Stuart Foster April 30, 2009 at 5:21 pm

The seeding aspect of this outline was particularly fascinating for me. Mainly because it’s probably the most difficult to identify those particular people that would be best suited for distributing this information. It’s even tougher when you are trying to deliberately get the ball rolling. Interesting stuff Dan…

Mat May 1, 2009 at 4:41 am

i think you might be reaching just a little bit…..interesting to read all the same!

Dixon Jones May 1, 2009 at 8:17 am

That’s a great analogy. Point seven is like a bolt of lightening really. It’s absolutely obvious when you see it, but before you see it, a successful viral campaign seems to be as much about luck as anything else.

What IS changing the paradigm is Twitter and social Networks of course. True – only (say) 1 in 100 people spread the word… so way less than 1 on 1… but if those people all have over 100 followers, then the maths is on the right track – because the infection used to be passed on on person at a time. Now the infection rate is one to many.

I guess the viral disease depends on whether you are just a carrier of the disease (you heard the message) or a super-infector, like the Typhoid Mart you mention. Malcolm Gladwell talks about this in his book – “Tipping Point” – calling thise super infectors “connectors” I think.

Lastly – I heard this on Twitter:
“I called up the swine flu hotline today, but all I git was crackling”
Boom! BOOM!


Michael D May 1, 2009 at 11:37 am

Excellent job organizing this Dan, and in list format too. Serves as a template for making sure all the components of a campaign are just right. Love it!

Andres R May 2, 2009 at 1:10 pm

Explaning viral marketing by comparing its practical theory to the Swine Flu outbreak or “Aporkalypse crisis” is a great meme!

Any methodological tips on how to mesure reproduction rates in order to establish if a campaign went pandemic or is still endemic?

Would that be accurate to use the term hypodemic for a campaign with a rep ratio lower than one?

Congrats for your article feature on the Financial Times (http://sn.im/h80qt)Dan!


Scott May 6, 2009 at 3:03 pm


There are many great lessons viral marketers can learn from the Swine Flu story. Thanks for summing a number of them into a single post.


EH May 6, 2009 at 3:58 pm

Wow, great comparisons between the Swine Flu and marketing. I love seeing the different takes and lessons marketers get out of events.

Mat May 8, 2009 at 4:12 am

Well, the article did serve its purpose, it got us to post responses! Keep it up ;)

atul chatterjee May 12, 2009 at 6:15 am

The point about seeding is the most important to me. The last point indicates that we act on a few users continuously rather than try and get a large number of people infected.
I was looking up the term viral marketing, it does not have an offline equivalent. However it smells vaguely like MLM and network marketing, only the channels are not there in these offline forms.

Cotton Rohrscheib June 1, 2009 at 10:41 pm

Awesome Post!!!

edisonsamuel June 2, 2009 at 2:37 am

yeah excellent comparison !
Good one

Health_Campus August 30, 2009 at 12:30 am

Thanks for sharing the information. I am very amazed at the confidence level of you guys, so i have to

refer your blog to my friends because it’s really a help full blog.
Good Day


dontcry December 22, 2009 at 1:42 am

I was looking up the term viral marketing, it does not have an offline equivalent. However it smells vaguely like MLM and network marketing, only the channels are not there in these offline forms.
club penguin cheats

dontcry December 22, 2009 at 9:42 am

I was looking up the term viral marketing, it does not have an offline equivalent. However it smells vaguely like MLM and network marketing, only the channels are not there in these offline forms.
club penguin cheats

Payday Loans April 21, 2010 at 10:15 pm

This is a great blog, i have bookmarked it. payday loan company

Nintendo64 June 18, 2010 at 1:17 pm

i know this is a bit late but there is an offline alternative in terms of street graffiti or stencil graffiti and things like that :)