The Secret Sauce of Viral Marketing: How to Make Your Product Contagious

The Art and Science of Creating Buzz and Going Viral

The Secret Sauce of Viral Marketing: How to Make Your Product Contagious
Photo by Yingchih / Unsplash

Do you ever wonder how startups like Dropbox, Canva, and Hubspot achieve rapid growth and become household names in a matter of years? The answer lies in the power of viral marketing, a strategy that allows companies to leverage their existing user base to reach new customers and achieve exponential growth.

Viral Marketing Tactic Description Example
Referral Program Rewards existing users for referring new customers Dropbox offers free storage to users who refer friends
Free Tools Provides users with a valuable free tool that encourages them to share with others Canva offers a free graphic design tool that users can share with colleagues and friends
Social Sharing Makes it easy for users to share the product on social media Hubspot offers social media sharing buttons on its blog posts
Giveaways Provides users with an incentive to share the product with others in exchange for a chance to win a prize Hootsuite offers a free t-shirt to users who refer new customers

But how do you create a viral effect? One company that cracked the code back in 1996 was Hotmail, one of the first web-based email services. Adding a simple tagline to the end of each user's outgoing email created a self-sustaining growth loop that led to explosive user growth. Since then, countless SaaS companies have followed in Hotmail's footsteps, using creative tactics to get users to spread the word and drive long-term success.

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In this blog, we'll dive into the story of Hotmail's growth hack and explore some of the top viral marketing tactics SaaS companies use today. From referral programs to free tools, we'll show you how these companies are leveraging the power of viral marketing to achieve rapid growth and reach new customers. Get ready to learn the secrets to viral marketing success and take your startup to the next level!

The Hotmail Story: How a Tagline Sparked Explosive Growth

Back in 1996, email was still a relatively new technology, and few people had email accounts. Hotmail was one of the first web-based email services, and they were struggling to get users to sign up. That's when they devised a clever growth hack that changed the game.

Hotmail added a tagline to the end of each user's outgoing email: "Get Your Free Email at Hotmail." When recipients clicked on the link, they were taken to a page to sign up for their Hotmail account. This simple tactic had a profound impact on Hotmail's user base. Within six months, they had over one million users, and by the end of the year, they had more than 12 million.

The secret to Hotmail's success was the viral nature of their growth hack. Whenever a Hotmail user sent an email, they inadvertently promoted the service to their friends and colleagues. This created a self-sustaining growth loop that fueled the company's rapid expansion.

Company Campaign Result
Dollar Shave Club "Our Blades are F***ing Great" video Generated over 12,000 orders in the first 48 hours
Old Spice "The Man Your Man Could Smell Like" video Increased sales by 107% in one month
Airbnb "One Less Stranger" campaign Encouraged hosts to offer free accommodation to strangers and generated over 1 million social media interactions

SaaS Examples: How Viral Marketing is Used Today

The Hotmail growth hack may have been revolutionary in its time, but today, it's a common tactic used by many SaaS companies. Here are some examples:

1. Slack

Slack is a team collaboration tool that has become ubiquitous in many workplaces. One of the keys to their success has been their referral program, which offers discounts to users who refer new customers to the platform. This incentivizes existing users to spread the word about Slack to their colleagues and friends and has helped the company achieve impressive growth in a crowded market.

2. Airbnb

Airbnb, the popular home-sharing platform, has also leveraged the power of referral marketing to achieve growth. By offering discounts to users who refer their friends to the platform, Airbnb has been able to tap into the social networks of its existing user base and reach new customers. In fact, the company estimates that referrals have driven as much as 25% of their new user growth.

3. Dropbox

While Dropbox may be a well-known example, it's worth highlighting its referral program as one of the most successful viral marketing campaigns in recent memory. By offering free storage to users who referred new customers to the platform, Dropbox grew its user base from 100,000 to 4 million in just 15 months.

4. TikTok

TikTok, the popular social media app, has also used a referral program to drive growth. By offering users the chance to earn virtual coins by inviting their friends to join the platform, TikTok has been able to tap into the social networks of their existing users and encourage new user signups.

5. Calendly

Calendly is a scheduling tool that makes it easy for users to schedule meetings without the back-and-forth of email. One of the keys to their growth has been their free plan, which allows users to sign up and start using the platform for free. This has helped Calendly to attract new users and build brand awareness, ultimately leading to more paying customers.


The Hotmail growth hack is a classic example of the power of viral marketing. By tapping into the network effects and leveraging their existing user base, Hotmail was able to create a self-sustaining growth loop that led to explosive user growth.

Today, SaaS companies continue to use similar tactics to grow their user base and increase brand awareness. By incentivizing users to share their products and services with their network, these companies can create a viral effect to help them achieve long-term success.