Dose #135: 9 Years of Lessons From Building Buster Box

Matt here with your weekly Subscription Prescription 💊

You won’t believe the gems dropped in this week’s dose. Liam Brennan, one of the founders of Busterbox, shares much of what he’s learned after 9 years in the subscription industry. We start with personalization, dive into offers, get into retention, and end with some quick tips from Liam.

This week’s dose is also a full interview with Liam Brennan that you cannot miss. Tune in on your favorite platform.

9 Years of Lessons From Building Buster Box

This interview blew me away. Sometimes, it’s challenging to find something every subscription brand should be doing based on what another brand has done. Not this time.

Liam has not only built Busterbox into a success but also hosts a subscription group and creates a ton of content. He knows his stuff, and I’m excited to share much of what we discussed here!

Let’s dive in.

1. Customer Personalization is Non-Negotiable

One-size-fits-all rarely works in subscription businesses. Customers expect a tailored experience, especially in categories like pets, beauty, or fitness, where personal preferences vary significantly.

Why does this matter? Without personalization, customers are likely to churn because they don’t see the value in sticking around. A generic experience signals to customers that they’re just another transaction—not someone you care about.

Here’s the solution: gather as much data as possible during the sign-up process and encourage ongoing feedback. Ask the right questions—whether it’s about their preferences, allergies, or specific needs—and make it easy for them to share updates later. This approach helps you craft a subscription that feels like it’s made just for them.

Busterbox is a curated subscription box, meaning they select the items that go in the box every month. But they ask people what they like and don’t like, and those responses influence what goes into a customer’s box each time.

2. Your Acquisition Offer Shapes Retention

The first offer a customer sees does more than just get them in the door—it can predict how long they’ll stick around. Deep discounts might lower your upfront cost to acquire customers, but they often lead to poor retention.

Why does this matter? Different acquisition offers attract different types of customers. If you’re focused solely on driving low-cost sign-ups, you may end up with more churn and lower lifetime value.

To address this, experiment with multiple offers and analyze their retention impacts. For example:

• “Double Your First Box” offers tend to attract high-quality customers who stay longer.

• Free gifts can work well but may require a higher acquisition cost.

• Deep discounts attract bargain hunters who churn faster.

Running multiple offers simultaneously and testing their effectiveness helps you optimize customer acquisition costs and retention rates.

The beauty here is that you don’t need a single offer to be successful. When you look at Busterbox’s website, for example, you’ll see different offers at sign-up because not every offer will work for every subscriber.

3. Make Upselling and Reactivation Easy

Every customer touchpoint is an opportunity to deepen engagement and grow revenue. However, many brands fail to optimize these moments, leaving money on the table.

Why does this matter? Retention isn’t just about keeping customers—it’s about maximizing the value of their relationship with your brand. Upselling and reactivating lapsed customers can significantly boost your bottom line without the high costs of acquiring new ones.

One effective tactic is the “Reply Yes” email process. Here’s how it works:

• Send an email offering an upsell—like a mystery box, extra items, or a prepaid upgrade.

• Customers can opt-in simply by replying “Yes.”

• Your team or system handles the rest, adding the extra items or updating their subscription.

This approach simplifies the buying process for customers, drives incremental revenue, and improves email deliverability since replies are engagement signals.

For those of you who follow my content, you know I love the new email tool Zaymo to make upsells easy. But with this approach, you’re boosting your email deliverability and making the experience feel more personal.

If you’re looking for more places to include upsells, I like these opportunities:

• In-cart with a key value-add offer

• Confirmation page

• NOT in the onboarding email series

• Renewal email notifications - upgrades to quarterly subs or add-ons

• Dedicated emails at months 3+

• Product inserts

Bonus Tips

We covered so much that I wanted to include a few more tips from Liam:

1. Prepaid Subscriptions: Offer a discount for 6- or 12-month prepaid plans. This boosts cash flow and locks customers in for the long term.

2. Reactivation Campaigns: Target churned customers who made at least six payments before canceling. Offer them an incentive—like a free item or a discounted rate—to return.

3. Focus on Metrics: Align your retention and acquisition teams to look at shared metrics like lifetime value (LTV) and cohort retention rates. It’s easier to grow when everyone is rowing in the same direction.

Your Prescription This Week

That’s it for this week’s dose! To make the most of all this, evaluate how well you’re personalizing customer experiences, optimizing acquisition offers, and leveraging upselling opportunities. These three levers can dramatically improve your retention and revenue.

Have a specific strategy that worked for you? Hit reply—I’d love to hear it!

Stay tuned for the next dose of Subscription Prescription next Tuesday!

 - Matt Holman 🩺

The Subscription Doc