66M Users in a Year: Growth Design Case Study

In 2022, Sweatcoin became the world's most downloaded Health & Fitness App

One of the features that helped to gain more than 66 million new users that year was our 'Scratch The Prize' referral feature.
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But before diving into this feature, let's first look at the backbone of our approach: The Sweatcoin Growth Engine.
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At Sweatcoin, growth design isn't just about "growth hacking"; it's a fusion of design thinking, marketing experimentation and data-driven strategies, all aimed at driving the app's growth.

Context

Sweatcoin is a fitness app that rewards users with digital coins for their steps. It's simple: you walk, earn 'sweatcoins,' and then spend them on a variety of in-app activities, including the marketplace and charities.

When I joined the Sweatcoin team, the app had 40 million users. ODuring my two years with the company, we saw remarkable growth, adding over 80 million new users.

Growth Team Structure

In Sweatcoin's growth team, I was the only Senior Product Designer and worked mainly with the organic (viral) growth team. Besides me, the team had two developers, a group product manager, and a QA specialist. We were the driving force behind in-app referrals, walking challenges and social sharing features.

There was also a paid growth team, handling affiliate programs, social media, and paid advertising, with a marketing manager, a graphic designer, and an influencer manager.

I was working across both teams ensuring that our growth engine and in-app features worked together seamlessly and aligned with the company's overall strategy.

Growth Design Process

Establishing an adaptive growth design process at Sweatcoin was challenging. We typically had three key stages: Investigate, Design & Collect Feedback, and Implement & Measure.

‍Investigate: This initial stage was fundamental. It involved setting clear goals for the new feature, conducting thorough research, leveraging past insights, and brainstorming solutions. We formulated growth hypotheses and prioritized the most promising ideas using the ICE (Impact, Confidence, and Ease) framework.

‍Design & Collect Feedback: Here, I developed user flows in Miro and crafted low-fidelity prototypes. This early version of the design was crucial for gathering user feedback before finalising the UI. Several rounds of feedback were conducted to refine the MVP designs, with a focus on ensuring feasibility and speed of development in collaboration with our developers.

‍Implement & Measure: Once the MVP was ready, we launched it to different segments of Sweatcoin users for a few weeks. This stage was critical for measuring the feature’s impact and effectiveness. Based on the data and user responses, we made informed decisions about further investing in the feature or pivoting to new ideas.

Each stage was integral to our growth design process, ensuring that every feature we rolled out was not only user-centric but also aligned with our growth objectives & team primary KPIs.

2022 Growth Design Impact

As mentioned earlier, 2022 saw Sweatcoin rise to become the most downloaded health & fitness app globally. A key factor behind this achievement was our implementation of growth design strategies during our expansion into new markets. Our growth engine was flexible, constantly evolving to adapt to new challenges.

Alongside this, my team focused on localising our app, which was vital for our smooth entry and strong performance in these new markets. Localisation involved more than just translating languages; it meant adjusting the design and content to the diverse cultural nuances and user preferences in each market. This careful and adaptive approach to localisation played a significant role in our success throughout 2022.

The killer feature: “Scratch the Prize”

Now that we've looked at Sweatcoin's growth design and team setup, let's talk about something big from 2022: our 'Scratch The Prize' friend referral feature. It was a huge hit and helped bring in over 66 million new users that year.

The concept was simple: users shared a unique link with friends, and each new registration through this link earned them a chance to scratch a digital card (lottery ticket) for cool prizes.

To ramp up the excitement, we offered compelling rewards like up to $500 in cash, AirPods, new iPhones, and in-app currency.

Now, let’s dive into how we crafted and rolled out this popular feature.

Problem with Motivating Users to Invite

Sweatcoin wanted to increase its viral growth. However, existing referral strategies weren't effective enough. Basic rewards didn't keep users engaged with the referral features, leading to low retention or high expenses.
The goal was clear: find a creative solution with the right rewards to encourage users to invite friends. Ideally, this solution would improve their experience, drive overall product growth, and control the desired Customer Acquisition Cost (CAC).

Solution: Invite-to-earn Variable Reward

Introducing the "Scratch The Prize" feature, not boring in-app referrals. This feature allowed users to scratch off virtual tickets, revealing various randomized rewards for each successful friend invite.
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It wasn't just about making invitations more engaging than the standard method; this feature also strategically helped us manage and reduce our Customer Acquisition Costs (CAC).

Design process

We followed our flexible growth design process for launching the 'Scratch The Prize' feature. The main steps in this process included:

1. Leveraging Past Insights

Our first step involved analyzing previous features that rewarded users for invites: the 'get 5 now' (5 sweatcoins per invite) and the 'piggybank' (cash per invite) feature.

These insights confirmed that our users were motivated by rewards, however, we needed to balance this with Customer Acquisition Costs (CAC).

2. Competitive Referral Program Review

Next, we researched the mass-adopted referral programs of popular apps such as Uber, Revolut, and Airbnb. Our goal was to understand what made these programs successful, focusing on their simplicity, reward type (cash or discounts), and ease of access within the app.

3. Brainstorming and Conceptualization

Armed with our competitive research, our growth team had a brainstorming session. It was here that I proposed a lottery-based approach, balancing attractive prizes with controlled Customer Acquisition Costs (CAC). This idea was well-received, and I proceeded to draft a 'happy path' in Miro, which helped us identify and discuss any potential development blockers with our developers.

4. Wireframing and Prototyping

Following the brainstorming phase, I developed initial wireframes and low-fidelity prototypes. This step was crucial for collaboration with our UX research team to gather user feedback.

5. Incorporating User Feedback

To validate our concept, we conducted user interviews and reviewed the prototypes with them. The feedback was overwhelmingly positive, with users expressing excitement about the feature and sharing their expectations regarding prizes and the invite process.

6. High-Fidelity Design and Finalization

Once we received a green light from user feedback, I shifted focus to high-fidelity designs in Framer. This stage involved deciding on finer details, such as choosing a gold colour scheme for its celebratory feel.

Collaborating closely with developers, I worked on creating visuals for the prizes and perfecting the scratching mechanism, ensuring both appeal and functionality. This phase was marked by extensive testing and iterations to achieve the desired outcome.

7. Testing and Launch

Finally, we tested the feature on different user segments, considering factors like lifecycle (new users vs long-term users), engagement (time spent in-app, frequency of use, daily steps), location (EN-speaking countries), and device type (iOS, Android).

Our primary KPI, Successful Invites, went up by 40%. Inspired by these results, we confidently launched the feature, aligning it with our market expansion strategy.

Note: Image for visualisation purposes only, not actual test results of the 'Scratch The Prize' feature.

Brazil Launch

The 'Scratch The Prize' feature was instrumental in our expansion into new markets, perfectly aligning with our localisation strategies and resonating with a diverse range of user groups.

One of the most notable successes was in Brazil, where we witnessed a remarkable growth of nearly 5 million new users within just 7 days, attributed to our referral features.

Summary

The 'Scratch The Prize' feature was a game-changer. In 2022, this feature was one of the key players in attracting 20 million new users, which was 30% of all our new sign-ups for the year.

Users loved scratching off the virtual cards and the rewards motivated them to invite their friends. What's more, it helped Sweatcoin slash its Customer Acquisition Costs: these new users were 200x cheaper and 50% higher retention than ads. My favourite side effect: Influencers loved promoting this feature to their followers. They finally had something to offer to their followers.

To me, it’s a testament to the power of mixing the right elements – business model, paid ads, affiliate programs, and smart referrals – to really ignite viral growth, especially in new markets, and achieve some mind-blowing results.

If you’ve made it this far, thanks for reading! I'm always here for questions or if you just want to chat about it.

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