End of Firebase Deferred Links: Next-Gen Referral Engines.

Google’s decision to sunset Firebase Dynamic Links is forcing app marketers and founders to rethink their deep linking and referral strategies. But rather than viewing this as a challenge, we see an opportunity - to build more sophisticated, monetised referral programmes and incentivised invite systems that drive exponential growth.

At Kurve, we have worked with leading apps to design highly effective referral engines that go beyond traditional deep linking. This is a chance to reinvent how you drive virality, increase your K-factor, and scale user acquisition sustainably.

The Opportunity: Rethinking Referral Growth and Community-Led Expansion

Many apps have relied on Firebase Deferred Deep Links to seamlessly onboard referred users. With this tool being deprecated, now is the time to reimagine referral and invite mechanics in a way that:

• Increases virality – Designing incentive structures that encourage sharing and community-driven adoption.
• Boosts retention – Creating referral loops that reinforce engagement and network effects.
• Drives revenue – Turning referrals into monetised growth levers through incentivised actions and in-app rewards.

Apps that get referral mechanics right see exponential user growth without the high costs of paid acquisition.

Many of the most successful apps today, from Revolut to Uber to Dropbox, scaled rapidly through referral-based mechanics, not just paid ads.

Want to understand how to measure referral success? Read our guide on K-Factor, Viral Coefficient, and Retention Rate to optimise your referral programme.

Incentivised Invites: Supercharging K-Factor and Viral Coefficient

Your K-factor measures how many additional users a single referrer brings into your app. The best way to improve this metric? Make sharing frictionless and rewarding.

Example Incentive Strategies

• Reward-based sharing – Users unlock in-app credits or exclusive perks for inviting friends.
  Example: Sweatcoin’s step-count-based reward system.
• Tiered referral rewards – Increasing the rewards the more users someone invites.
  Example: Revolut’s multi-tier cash bonus system.
• Exclusive access models – Early invite-only access or VIP perks for users who refer friends.
  Example: Clubhouse’s invite-based viral.
• Limited-time bonus boosts – Short-term promotions where referring a friend offers double rewards.
  Example: Uber’s short-term surge in referral payouts.

How We Implement it at Kurve

• We use smart deep linking solutions to track referrals seamlessly across platforms.
• We build gamified mechanics that encourage ongoing referrals beyond first installs.
• We A/B test different referral incentives to maximise K-factor efficiency.

Recommended Tools for Referral Tracking

• Branch.io – Referral and deep linking solutions
• Adjust TrueLink – Deep linking and attribution
• Airbridge – Deep link tracking and analytics

Case Study: A client saw a 42% increase in organic installs after implementing a referral-based onboarding model with incentivised invites.

Monetised Referral Engines: Turning Word-of-Mouth into a Scalable Growth Model

Incentivising referrals does not just drive growth, it can generate revenue directly by integrating monetisation strategies into the referral flow.

Monetisation Models That Work

• Cashback and profit-sharing – Users earn a percentage of revenue from their referrals' purchases.
  Example: Rakuten’s referral-based cashback model.
• Affiliate-like commission structures – Turning users into brand ambassadors with payout-based referrals.
  Example: Robinhood’s stock rewards for referrals.
• Unlocking premium features – Referral-based access to premium content or advanced app features.
  Example: Duolingo’s free Super subscription via referrals.
• Tokenised reward systems – Referrers earn in-app tokens that can be redeemed for real-world benefits.
  Example: Sweatcoin’s tokenised health rewards.

How We Build This at Kurve

• Integrate referral tracking tools like Branch.io or AppsFlyer for seamless user onboarding.
• Design reward structures that drive engagement without harming unit economics.
• Implement A/B testing to fine-tune reward payout thresholds for profitability.

Case Study: With a client launching an “Invite and Earn” model we saw a 34% increase in app engagement by tying referrals to exclusive content access.

Leveraging Community and Social Virality for Growth

The strongest referral programmes do not just reward users; they turn them into brand advocates.

Community-Led Growth Strategies

• UGC-driven referral loops – Encouraging users to share experiences online.
  Example: TikTok’s “invite friends to unlock features” campaigns.
• Social contests and challenges – Rewarding users for inviting friends and engaging with content.
  Example: Sweatcoin’s challenge-based referral events.
• Influencer-led invite programmes – Leveraging micro-influencers to drive viral referrals at scale.
  Example: Commons’s eco-conscious influencer ambassador programme.

How We Help Apps Build Community Growth

• We create UGC-focused referral mechanics that feel organic, not sales-driven.
• We leverage influencers to amplify invite-based challenges.
• We test social-based rewards, such as exclusive group unlocks for multi-user referrals.

Our Process: Designing and Implementing Scalable Referral Engines

Step 1: Audit and Strategy Development

Assess your app’s current K-factor, viral bottlenecks, and referral friction points.

Step 2: Referral Programme Design

Develop custom incentive structures (monetised, points-based, or tiered rewards).

Step 3: Deep Linking and Tracking Setup

Implement Branch.io, Adjust, or Airbridge for seamless referral tracking.

Step 4: A/B Testing and Performance Optimisation

Run controlled experiments to identify high-performing referral triggers.

Step 5: Scale and Iterate

Expand referral mechanics through social amplification, influencer marketing, and UGC loops.

Want a tailored referral strategy? Get in touch.

How do I measure the success of my referral programme?

Key metrics include:

• K-Factor – how many users each referrer brings
• Viral Coefficient – the compounding effect of invites
• Retention Rate – referred users vs. non-referred users

FAQs: Firebase Sunset and Referral Growth Strategies

Q1: What is happening to Firebase Deferred Deep Links, and when will they stop working?
A: Firebase has announced that Deferred Deep Links will be deprecated, with full support ending by August 2025. This means any existing links created through Firebase may cease to function, affecting how you acquire and onboard new users via referral programs.

Q2: Why is Firebase discontinuing Deferred Deep Links?
A: Google is likely shifting focus to new products and services that better integrate with their overall ecosystem. While the exact reasons haven't been disclosed, it often reflects a strategic move to encourage users toward more robust, scalable solutions that offer better analytics and cross-platform support.

Q3: What are my options for deep linking now that Firebase Deferred Deep Links are sunsetting?
A: You can transition to third-party solutions like Branch.io, Adjust, or Airbridge. These platforms offer advanced deep linking features, better analytics, and enhanced tracking capabilities, allowing you to create seamless user experiences across web and mobile.

Q4: How do I migrate my existing deep links to a new platform?
A: Migration typically involves:

• Mapping existing Firebase links to new links created in your chosen platform.
• Updating your app code to handle new deep link formats.
• Testing extensively to ensure a seamless user experience.
  Most third-party services offer comprehensive guides and support for migration.

Q5: Will my current Firebase links stop working immediately?
A: No, they will remain functional until the deprecation deadline in August 2025. However, it's crucial to start planning your migration strategy now to avoid disruptions in user acquisition flows.

Q6: How can I ensure a seamless user experience during this transition?
A: Maintain both sets of deep links during the transition period. Monitor and test them extensively to ensure users land on the correct content, whether they come from old Firebase links or new third-party ones.

Q7: What impact does this change have on my referral programme?
A: If your referral strategy relies heavily on deep links, you may face disruptions in user onboarding and tracking. Migrating to a new deep linking provider will not only maintain your referral flows but can also improve them with enhanced analytics and more sophisticated attribution.

Q8: Can I still measure the success of my referral programme without Firebase Deferred Deep Links?
A: Absolutely. In fact, this transition is an opportunity to enhance your referral tracking by integrating with platforms that offer deeper insights, such as:

• K-Factor – Measure how many new users each referrer brings.
• Virality Coefficient – Evaluate the compounding effect of invites.
• Retention Rate – Compare engagement between referred and non-referred users.
  Learn more about these metrics in our comprehensive guide on How to Measure Referral Success.

Q9: Are there alternative strategies I should consider beyond deep linking?
A: Yes, you can explore other growth strategies, including:

• In-app referral prompts that encourage users to share directly from your app.
• Email or SMS-based invites that link directly to app stores.
• Web-to-app smart banners that guide users to download your app from your website.

Q10: What are the benefits of switching to platforms like Branch or Adjust?
A: These platforms offer:

• Advanced analytics for better tracking and attribution.
• Customisable user experiences that can be tailored based on referral sources.
• A/B testing capabilities to optimise referral flows and improve conversion rates.

Q11: How do I decide which deep linking solution is best for my app?
A: Consider factors like:

• Cost: Evaluate pricing models based on your expected link volume.
• Integration: Look for platforms that seamlessly integrate with your existing tech stack.
• Features: Prioritise platforms offering detailed analytics, fraud prevention, and user-level attribution.

Q12: Can my team handle this migration, or do I need external help?
A: It depends on your internal resources and expertise. While in-house teams can manage the transition, leveraging agencies with experience in deep linking and app growth—like Kurve—can streamline the process and ensure best practices are followed.

Q13: Will this affect my app store rankings or SEO?
A: Properly implemented deep links can actually improve your app store optimisation (ASO) by enhancing user experience and engagement metrics. SEO remains unaffected as long as web-based deep links are set up correctly.

Q14: What should I prioritise during this transition?
A: Focus on:

• User experience: Ensure links guide users to the correct content.
• Data integrity: Maintain accurate referral tracking.
• Performance monitoring: Use analytics to assess the impact of new deep links.

Q15: How soon should I start preparing for this transition?
A: Begin planning now. Early preparation allows ample time for testing and ensures you won't face disruptions when Firebase Deferred Deep Links are fully deprecated.

Q16: Are there risks associated with not transitioning from Firebase Deferred Deep Links?
A: Yes. Ignoring the migration can lead to broken links, a poor user experience, loss of referral tracking, and ultimately, reduced app installs and user engagement.

Q17: Can I use this transition to improve my referral programme?
A: Absolutely. This is a prime opportunity to evaluate and upgrade your entire referral strategy, leveraging new tools and techniques to drive better results.

Final Thoughts: Reinventing Referrals for 2025 and Beyond

The sunsetting of Firebase Deferred Deep Links is not just a migration issue, it is a chance to build a next-generation referral engine that scales.

Ready to build a scalable referral programme? Let’s talk.