Flavors of Virality

September 16, 2020
Michael Taylor

If you plan to use viral growth as a channel, what are your options? There are 7 fundamental types of virality, or flavors, and they're all a little different.

Getting just one to work is a multi-million dollar achievement — chaining multiple methods together puts you among the fastest growing companies in history. Once you know how they work, and who they worked for, you can decide what to test for your business.

1. Network effects

Social networks like Instagram and Snapchat are only useful when other people are using them. If you loaded up TikTok and there were no videos to watch, it wouldn't be much fun.

In fact, Metcalf's Law says the usefulness of a network increases exponentially — two people can make only 1 connection, five can make 10 connections, and twelve can make 66 connections.

With this type of virality, your users invite their friends and colleagues through self-interest. The product gets inherently better for them the more people they invite.

Because these platforms are often linked to identity, users are further incentivized to share because of what it says about them, and their relationship with you. Inviting your friend to Clubhouse tells them you're a 'tech insider', and that you think they're worthy too.

Products that build network effects can become incredibly valuable, and difficult to compete with. No matter how much you hate Facebook, you can't easily delete your profile, because that's the one platform everyone you know is on.



This is where there's the opportunity to connect with people outside of your circle of friends or colleagues. Examples in B2C include TikTok, where your videos are show in the feeds of people you don't yet follow, Meetup.com where you can find events and meet people based on your interests, and video games like Fortnite, where you can be paired up with players you don't know. On the business side you have social networks like LinkedIn, in-person events like South-by-Southwest and video call tools like Zoom.


This is a strong form of virality, because the product just doesn't work if just your friend group or coworkers are using it. Because of this, external virality faces the 'cold start' problem — in the beginning nobody is using it, so it's not very useful. At scale these products can become near impossible to compete with.


This is when the network is primarily for connecting inside your friend group or company. Examples on the consumer side include messaging apps like Whatsapp, games like online Poker or group experiences like Wine tasting. For B2B you also see messaging apps like Slack, productivity tools like Asana and analytics platforms such as Amplitude.


These companies tend to 'land and expand' — growing virally once they enter a group, but with the aid of other growth channels to drive the initial introduction. This is a weaker form of virality because it's limited by group size, but still can drive significant value.

2. Casual Contact

This type of virality occurs when a public-facing aspect of the product exposes new potential users to its functionality or branding. The classic example is Hotmail, which put "Get your free email at Hotmail" at the bottom of each email its users sent. With users sending hundreds of emails a month, this served as free advertising. Many companies design this explicitly into their products as a way to engineer virality.


Like the Hotmail example, this is when the product displays their branding as the product is used. For example the bag your jeans come in have the logo of the store, the "powered by Sumo" badge you see on email popups, or the Uber or Lyft signs displayed by drivers of the service.



This is where functionality of the product is 'embedded' in another platform by the user. For example news articles often make use of Twitter's embedded tweets feature, MixMax embeds a calendar in emails the user sends to schedule meetings, and Airtable allows embedding of their spreadsheets in webpages. This is different from simply displaying branding, because some functional, interactive part of the actual product is being used externally.


3. User-Generated Content

This is one of the most powerful forms of virality — when your users create content which by nature advertises your service on other platforms. Good examples include Yelp, where user's reviews help it rank on Google, Youtube, where the best videos get shared widely across social media and Google Docs, which users create then share via email.


Because only a small percentage of users on the internet create, this is a very difficult flywheel to get started. Creators don't want to waste their time on a platform that can't bring them attention, whilst you can't bring in users without content. Once turning, this growth loop can lead to exponential growth.

4. Word of Mouth

This is the original marketing channel — and still the most trustworthy. Before we had mass media or even writing, every new product was communicated via word of mouth.

Branding was invented to supercharge word of mouth. If you can encode the identity of your product in a distinctive symbol, it'll be easier to spread with less work — and they'll remember it better too.

This is the dream form of virality for marketers, as it's a sign your product is so good people can't wait to tell their friends about it. Every product has some element of word of mouth, though it can be difficult to track and attribute this behavior.

Social Sharing

The most measurable form of word of mouth is online social sharing. When users mention your brand on Facebook, Twitter, LinkedIn, they're doing your marketing for you. What gets people to share on social media? Jonah Berger, author of the book Contagious, lists 6 options:

  1. Social Currency – “We share things that make us look good"
  2. Triggers – “Top of mind, tip of tongue”
  3. Emotion – “When we care, we share”
  4. Public – “Making things more observable, makes them easier to imitate”
  5. Practical Value – “News you can use”
  6. Stories – “Information travels under the guise of idle chatter”

One valuable tactic for prompting social media sharing is the use of Easter Eggs — including something unexpected and unadvertised in your product. For example the cookie your hotel gives you on checkin, Google's doodles based on current events, or when you search for flights to Las Vegas on Hipmunk and the text changes to "Vegas baby!".


Dark Social

The truth is that sharing on public social networks is just the tip of the iceberg. Private sharing on via Whatsapp, Email or Slack account for as much as 69% of traffic according to Alex Madrigal of the Atlantic. We can't easily track this (until now) because these platforms don't pass a marketing source or referrer — they show up as 'direct' traffic in analytics platforms.


Offline Sharing

Like any good advertisement, you want their pitch to be accessible, memorable and emotional — except unlike an ad, you can't control the script. This is developing a strong brand can help. If they could only say one or two things about you, what would they say? Who would they say it to? If you interview two employees at random and they answer differently, you have a problem. Make sure your visual assets are consistent too  — a distinctive color like Monzo's bank cards can grab attention.


5. Incentivized

Knowing how valuable viral growth can be, many companies attempt to incentivize it. In fact, that's what the entire affiliate marketing and influencer industries are built on! Other popular avenues include discounts for sharing, giveaways and competitions, as well as trading status or access to content or premium features. Primarily these incentives consist of one of 3 categories.

  1. Money — $10 for every friend you sign up, PayPal
  2. Content — Free in-game holiday items, Farmville
  3. Features — Invite 7 friends for unlimited tracking, MixMax

You must be careful with incentives, as they can lead to fraudulent behavior or bring in low quality leads. Additionally, don't expect to just add a sharing incentive to make your product go viral. If users aren't already sharing, this isn't likely to get them to start, only motivate them more if they already like your product.


6. Public Relations

Often when a product seems to have 'gone viral' it's often just being promoted by people or organizations that have large audiences. The art of working with and coordinating with these people (without letting the story get away from you!) is a skill all to itself.

PR and influencers rarely exhibit true virality — where 1 user spreads to 2, who spread to 4, who spread to 8. Instead it usually looks more like a spike, followed by very steep decline, as everyone moves on to the next story.


Publishing companies, television shows and newspapers have daily audiences in the millions — and once a story is picked up in one place, it tends to get syndicated out to other places who don't want to miss out. Hire an expensive PR firm, and you can very easily end up with features in top publications. Or try your hand at PR hacking — manufacture a story tangential to your business on a slow news day, and you can help time-poor journalists fill their pages.



These days many influencers have larger followings than these publications, and can often be more directly incentivized to share (though this can be expensive and hard to track). Mega influencers such as celebrities can generate millions of sales overnight, and companies often contract with them for use of their endorsement for marketing materials in other channels.


7. Freemium

If your product isn't inherently viral... release a free product that is! The freemium option has worked for multiple companies in industries as diverse as file-sharing (Dropbox), casual gaming (Clash of Clans) and web analytics (Hotjar).

Most inbound or content marketing initiatives could be categorized as freemium — you're giving away valuable information for free on your blog, because blogs are more easily shareable than your paid product or service. There is also engineering as marketing, such as creating calculators, widgets or other free tools that people share.


What's best for my business?

Many businesses try at least one flavor of virality, and the majority of successful businesses see a significant number of customers coming at least via word of mouth.

Some types of industry or product are better suited to different types of virality. If you're creating a social network and you don't grow virally through invites, then you probably have a problem. Whereas boring corporate B2B software categories might need to lean on freemium products to generate buzz.

You may never get to the famed K-Factor of >1 (where each new person brings at least 1 more with them, leading to exponential growth), but any increase at all in virality goes straight to the bottom line. 10% more referral traffic means every channel now works 10% better for you.

Even small percentages compound, because virality brings more people, who themselves will share, and so on. So experiment with different options, though be quick to abandon them if you don't see traction — you can always come back and test it again later when you're better known.