Since we are moving into the age of social media, I thought maybe I would share some of my notes on what it really means to go 'viral'.  I failed math so if anyone is an excel sheet wizard and wants to incorporate everything into one big spreadsheet, it might be really useful to a lot of us to figure out what kind of potential our social media strategies might have, in terms of WOM marketing.

This is what I have on the subject:

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From David  Skok
This is the Mac Daddy of Viral Marketing Math ...and it's way too complicated to cut and paste and it has embedded spreadsheets in it as well, so just go here:
http://www.forentrepreneurs.com/lessons-learnt-viral-marketing/

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From dogboy

These are some of the variables which comprise 'the Viral co-efficient':

- the value of the information to the avg person, relative to what news is out there currently, and what is conceivably possible. Is this a big deal to me? Is this a big deal to others around me/I know/can tell?
- the number of channels the info can flow from the initial source to the total audience (TV, Radio, Newspaper, or just during the half time show during the superbowl?) as well as the 'total reach' expressed as a percentage of the total population. There is still 10%? maybe you can't reach within X timeframe.
- Fidelity, which is tied in part to the complexity of the information. Will the person understand what is being explained to them? Or will the message degrade from transmission to transmission?
- the number of initial dissemination points. Great news/terrible dissemination = failure, lame news/incredible dissemination = possible success, etc.)
- the value of sharing this information with others, usually expressed as the avg shares per individual ...which partially hinges on the number of channels the info can flow from the downstream sources to other downstream sources who are already not aware of whatever you are trying to show them.
- Time. How long is the duration of viral-ity? Is there a build up before hand, like New Years? Is it flash news that becomes useless just as fast? Or something that will hold people's attention for days/weeks/years? I's it a race with a start and a finish, or does it run until it just peters out and dies?
- Authenticity. Who told you the sky is falling? Drunk bum, or your best friend? (unless the drunk bum is your ...
- Orchestration. Was this spontaneous, or planned carefully to maximize all the synergistic feedback cycles possible?

...the problem is my math has no numbers:(

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From Noah
http://www.noahbrier.com/archives/2007/06/the_math_of_viral.php

"The network effect says that the value of that Ethernet card to the person on whose desk it sits is proportional to the number, N, of other computer users he can connect to. Now multiply this value by the number of users, and you have a value for the whole operation that is roughly proportional to N2." In plain English: If one person has a fax machine it's got no value, if two people have it, it's still got very little value. From there, however, the value really starts to grow for everyone involved and eventually it hits a 'tipping point' (or 'critical mass crossover') where some serious growth kicks in.



"In the old days of media buying you bought the number of impressions you wanted. It was a fairly straightforward equation: Value = cost, and cost is based on number of impressions (N) times CPM (cost per thousand impressions). 'Viral' tries to beat the system, however: By tapping into the network effect a marketer can gain far more value than cost. That's because while cost is still a constant, value grows exponentially based on the number of people who the 'viral' touches (that is assuming it is spread-worthy).

"if you lower the cost, you actually lower the 'critical mass crossover'. Basically, 'going viral' is not an absolute, rather it's based on the cost of production. If you make something for $5 than the 'critical mass crossover' is far lower than spending $500,000. This is possible because all power laws are scale-free, meaning no matter where you look at them they're exponential growth.

"The way I've been explaining scale-free to people lately is with exponents. 22 = 4 and 42 = 16 and 162 = 256. When you look at those four numbers (2, 4, 16, 256) you think that exponential growth kicks in when you square 16, I mean the jump between 16 and 256 is huge. However, if you just isolate 2, 4 and 16, the jump between 4 and 16 is also huge. While each jump is more radical than the one before it, they are all radical in their own right."

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From Seth:
http://sethgodin.typepad.com/seths_blog/2007/08/elephant-math.html

"Real viral growth comes from one of a few likely paths:

    * Someone sneezes your idea with amplification. They show up on Oprah, or you have $100 million to spend on ads. Great work if you can get it...
    * The idea spreads with fidelity. One person really does tell four, and there's not a lot of leakage. Starbucks worked this way, largely because the chain grew at just the right rate and kept its character as it did.
    * The idea is particularly 'viral' (using a popular understanding of the word.) One typical person doesn't tell four, she tells 400. This is the blogger effect--lots of small amplifiers, working in unison.
    * The idea lives a very long time and spreads slowly. In our rapid-fire world, this one is pretty rare.

Summary:
"it doesn't matter much how many elephants you start with. In other words, big launches don't necessarily scale. What matters is how fertile your elephants are (number of babies per generation) and how long they live."

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From Melissa Miller:
http://blog.hubspot.com/blog/tabid/6307/bid/9249/Understanding-Viral-Growth-Marketing-Math.aspx

"You can use the model to project how quickly an application will gain adoption based on these variables:

   1. Initial number of users (1,000 in Gmail's case)
   2. # of invitations each user sends to his friends
   3. %  of invitees who convert to users
   4. Cycle Time: # of days from the time someone first sees the application to the time his invitee sees the application

"Based on these inputs, Gmail experienced an enviable conversion rate of 21%:


''Summary:
    * Make an application that is easy to share
    * Encourage your users to share it; consider giving incentives for sharing.
    * Create an application with value that is so compelling, your customers will be happy to share it with others!"

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From Matt:
http://www.heinzmarketing.com/matt-on-marketing/blog/2009/12/only-math-you-need-to-make-your-ideas#

"As long as the coefficient is greater than one, your idea spreads.  And spreads.  And spreads."