Win Report: When a test wins, double down (for 22% more subscriptions)

Published: July 2025

Win Reports help you grow your business by showing our methodology at work. Each Win Report showcases a real-world test, sharing the research, insights, and techniques that led to the win.

If you’ve read our previous Win Reports, you may remember how we increased Optibac’s subscription sales by 39% when we added four bullets. That was a fantastic result, but conversion optimization is a continual process. When you find a strong lever, it pays to keep testing.

In the next three minutes, we’ll show you how a second “bullet test” increased subscriptions by a further 22%.

Optibac is the UK and Ireland’s most recommended seller of probiotic supplements. They have spent the last 20 years making high-quality live cultures scientifically proven to complement the natural microbiome. They have also won the UK’s highest award for business twice.

Research: When a test wins, double down

In addition to standalone products, Optibac sells subscriptions that offer lower prices and free delivery. This is a win-win for regular users, but customer research showed that users were concerned about “subscription lock-in.” In our user testing, they said things like:

“I’m worried that I’ll end up with too much, and it’ll be a hassle to cancel my subscription.”

The original winning page added four bullets right beneath the subscription box that:

Delivered reassurance at the right moment.
Reflected the customer’s language.
Emphasized the ease of cancellation.

Step 9 of our methodology involves transferring winning campaigns into other media. Following our previous win, we tested the new bullets (and some variations) in Optibac’s email campaigns. They won there, too, with simpler variations performing particularly well. (As we’ve said before, clarity is a hallmark of great CRO.)

What would happen if we took the insights from the email campaigns back to the website?

The original page (or control)

The previous winning page became our control for this test. Here’s the order form with the four bullets.

The bullets were already fairly brief, using bold text to aid scanability:

Commitment-free. Cancel anytime (with a click of a button).
Hassle-free. Easy to skip deliveries.
Get only what you need, exactly when you need it.
Save 15% ongoing, plus FREE UK standard delivery.

The tested page (or variation)

Based on the results of the email campaigns, we decided to test a simplified variation of the website, using shorter copy and fewer bullet points.

In addition to being shorter, the new bullets moved the key points to the front of each bullet, leading with the savings:

15% off and free delivery on every single order.
Change delivery dates to suit you - bring forward or delay.
Pause, skip or cancel anytime with our flexible platform.

Result: New subscriptions increased (again) by 22%

During the test, we observed a further 22% increase in new subscriptions.

The power of compounding wins

The previous test increased subscriptions by 39%. This second test added a further 22% uplift, not from the original baseline, but from the already-improved version. Combined, the two tests delivered a total increase of roughly 70% compared to where we started. This compounding effect is one of the reasons conversion optimization can deliver such extraordinary long-term gains: each win creates a stronger foundation for the next.

In addition to delighting our friends at Optibac, the result demonstrates three important aspects of CRO:

Winning tests are often signposts to other winning tests. (This is why our Wins Database is one of our most prized assets.)
Winning tests can often be transferred to other aspects of the business.
Even minor copy changes can have a profound impact on your conversion rate.

If you want us to grow your profits—quickly and efficiently—check if you qualify for a free one-on-one strategy session with one of our CRO consultants.

We’ll only work with you if we believe we can get amazing results together. Our success has come entirely from positive word of mouth, and we plan to keep it that way.

Thanks to Optibac for letting us share these insights (and for being such a great team to work with).

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