The ‘Death Curve’ for subscription brands
12 Jun 2025
3 min read
If you’re a subscription brand, or a brand that relies a lot on repeat orders, then you need to know about the death curve. This article tells the story of how brands can overcome the death curve and achieve sustainable growth.
Think of your brand as a car racing on specially designed tracks, with the founder as the driver. Just like a car must navigate high-speed curves and challenging ground, a subscription brand faces intense force and must maintain control to avoid spinning out. The journey up the death curve tests both the car and the driver, demanding skill and resilience to stay on track and reach sustainable growth.
The death curve is a term coined by Jay Myers at Bold Commerce. It marks a critical event in the lifecycle of a subscription brand, where you are consistently acquiring new customers or subscribers, but you are not achieving growth. It means that you can never achieve escape velocity as a brand and build sustainable growth.
Basically you grow and grow (move up the curve) until you hit a limit, and then you start to plateau. The speed of customer acquisition can get you up the curve quickly, but a bad stretch where growth stalls can occur if you can’t maintain momentum. This is because the customer acquisition cost (CAC) grows too large to be maintained with a similarly high churn rate – the rate you lose subscribers.
It doesn’t matter if you improve your acquisition if you are just not keeping the customers you acquire well enough. Your curve may go higher, but you still start to flatline. Gaining control over both CAC and churn is essential to avoid falling into the death curve.
While most founders obsess over:
Reducing CAC
Lowering churn
Increasing LTV (lifetime value)
The truth is that these are not enough to escape the death curve because you are acquiring as many customers as you are losing. To escape, you need organic customer referrals. Let’s explain.
What does the death curve look like
We recently attended a talk from Bella & Duke, one of our customers, who explained the death curve in detail. Here’s what it looks like.
So imagine that you start at 0 subscribers, and you acquire 100 a month, with a 10% churn rate. Think of your business as a car on a test track, with you—the founder or marketer—as the driver steering through each challenging curve. The route of subscriber numbers over time follows a specific path, much like a vehicle navigating a test track, where the ground conditions—the business environment and market forces—affect how well your car performs and how much control the driver must exert.
Now imagine if you double your acquisition. The curve is the same, only it reaches higher, but ultimately you still flatline. This is the same if you 2x or 10x your growth. Even with high speed growth, you eventually hit the same limit. In short, you can’t acquire your way to growth.
So let’s look at decreasing churn. Let’s reduce the churn to 8%. What this does is extend the death curve, where we reach flatline later. This is the same regardless of how low you make your churn rate. Each scenario represents a different track, with its own trajectory, but the end result is similar.
Now imagine that we add in referral rate. This is how many new customers each existing customer refers to your business, on average. Let’s assume that this referral rate is 0.5, so for every two existing customers you have, they refer one more. This means the death curve shape is still broadly the same. As churn increases, the force exerted on the business becomes greater, making it harder to sustain growth.
But now, let’s imagine that referral rate is instead 1.2 (up to now we’ve assumed it was 0). Now let’s look at the original company with 100 new customers a month and a 10% churn. All of a sudden the curve looks like this:
Now, the subscriber growth curve looks exponential, and all of a sudden there is no death curve. The inflection point where growth plateaus is like a bend in the curve—if you can get past it, you avoid stagnation.
So the answer is clear. If you are a subscription brand, the way to achieve growth is through referrals.
The viral coefficient
The key metric to remember is the viral coefficient, this is the number of new users an existing user generates.
This is:
the number of invites sent per subscriber x conversion rate = viral coefficient
The number you need to achieve here is >1. Anything greater than 1 avoids the death curve. Anything below leads to it.
How to grow referral rates
To find a solution to low referral rates, it's important to evaluate how your current program is set up.
We can confidently predict that you probably have a refer-a-friend incentive. But you are probably not achieving viral growth. That may be because your incentive is not that… enticing. Referral programs are typically installed in most subscription businesses, but their effectiveness depends on how well they are executed.
So here is how you can do it. These strategies can be carried out by your marketing teams to maximize results.
Finally, remember to continually test and optimize your referral program to ensure ongoing growth.
Make your referrals feel unique.
If you are giving customers a personal code to get 10% that they blast out on social media, then that doesn't feel valuable. If you are giving them 5 unique invitations for a friend, then they'll stop and think about who to give it to. That means they're more likely to pick a valuable future customer for you.
Make your referrals valuable
10% off may not cut it. What about 1 month free, or 2 or even 3? If you can get a highly valuable new customer organically, then 2 months free could well be worth it. The point is that you need to keep your viral coefficient over 1. So you don't need every customer to be referring 10 more each, just more than 1. So give as much as you can.
Track your super-referrers
Some people just have a great network. Imagine you are selling protein powders and supplements for workouts. Your best referrers are likely to be personal trainers or people who go to the gym a lot. They are always meeting new people, and are in a great position to refer. By monitoring each referrer's account, you can identify which individuals are your top performers and track their referral activity more effectively.
In summary, focus much more of your time on referrals, and less on acquisition or churn
The calculations are pretty simple. A major increase in acquisition numbers or a major reduction in churn rate are much less powerful than a modest increase in referral rate.
If you are focusing the majority of time on acquisition and churn then you are missing an opportunity, and you are heading straight for the “death curve”.
Read the Bella & Duke case study today.
