The most interesting CRO experiments are rarely the dramatic ones. People tend to imagine conversion rate optimisation as a series of big bets — rebuilding entire funnels, rewriting sales pages from scratch, redesigning the checkout experience, introducing completely new offers.

And sometimes, yes, that's what the situation calls for, but in my experience working with 100+ course businesses, the improvements that move the needle most tend to be surprisingly small. They come from understanding one very specific moment in the buyer journey and removing a single piece of friction that most people walk right past.

This case study is about one of those moments.

The context

The funnel we're talking about today already had decent numbers. The order bump (a complementary training offered at checkout) was converting at around 17%. In many course businesses, that number would be a win, but I've seen these offers perform at 40% and above, so 17% told me there was room.

The checkout is one of the most sensitive points in any funnel, and even modest improvements there compound quickly because they apply to every transaction passing through the system. So the question wasn't "how do we redesign this section?" It was simpler: what is the smallest change we could test that might make this decision a little easier?

To answer that, you have to start with what is actually happening in someone's mind at checkout.

What the buyer is doing at this exact moment

If the sales page did its job, then by the time someone reaches checkout, the main decision has already been made. They've accepted the price, the promise, and the value proposition, but then an order bump appears, and even a well-written one can interrupt that momentum.

The buyer is being asked to evaluate something new when they're already mentally committed to moving forward. They're tired from one round of decision-making, and now they're quietly running through another: What is this? Why does it matter right now? How is it different from what I'm already buying? And even when the price is low, is this worth the additional risk of being wrong?

That last question is the one most people underestimate. Hesitation at checkout isn't usually about price, i's about perceived risk. The buyer has momentum going in one direction, and the order bump introduces a small but genuine moment of caution. The instinct to avoid unnecessary mistakes kicks in, even when the stakes are objectively low.

So the hypothesis was straightforward: what if we could reduce that perceived risk at the exact moment the buyer is weighing it?

The diagnostic: a trust gap hiding in plain sight

When I looked closely at the checkout, something stood out. The main offer had a money-back guarantee, it was mentioned in the sales copy and visible on the checkout page. But the order bump had nothing: no guarantee, reassurance, or signal that trying this additional product carried any protection at all.

This kind of gap is easy to miss. The guarantee is there, so it feels like it's covered, but from the buyer's perspective, the order bump is a separate decision, and at that moment, they're on their own.

The change

We introduced a visible 30-day money-back guarantee badge directly on the product imagery within the order bump section. The design was simple, not a bright starburst demanding attention. The goal was to remind the buyer, at precisely the moment they were weighing the decision, that trying this additional product carried no real risk.

Everything else stayed the same: the product, the price, the copy.

The result

Order bump conversion moved from roughly 17% to just over 31%.

A 14 percentage point increase from one small visual change.

To make that concrete: on 100 checkout transactions with a $97 order bump, that's the difference between collecting $1,649 and collecting $3,010. And the only thing that changed was whether the buyer felt safe enough to say yes.

What this tells us about buyer psychology

The result is interesting, but what it reveals about how people make decisions is more useful.

During checkout, the brain is managing two competing forces simultaneously:

• On one side: momentum. The buyer is already purchasing something and they're mentally prepared to move forward. 
• On the other side: caution. The instinct to avoid unnecessary additions, to not be foolish, to not overcommit.

A guarantee doesn't eliminate that caution, but it reframes the decision from "Is this extra product worth the risk?" to "Can I try this without risk?" That shift, subtle as it sounds, is often enough to move someone from hesitation into action.

The principle behind the tactic

The important insight here is placement. Most businesses already have a guarantee, but a guarantee only influences behaviour when it appears at the moment the buyer is actually evaluating risk.

The reassurance has to meet the buyer where the hesitation lives, that's why we place money-back guarantees near call-to-action buttons and pricing panels — and why the same logic has to extend to every commitment point in the funnel, including order bumps.

This experiment is a good reminder of what conversion optimisation actually is, at its core. It's not about redesigning things that aren't broken, but about observing the buyer journey closely enough to find the exact place where hesitation appears, and then making the smallest possible change that resolves it.

Want to find the gaps in your checkout?

This kind of work — identifying the specific moments where buyers hesitate and designing targeted fixes — is exactly what I do in CRO audits and ongoing optimisation work with course businesses.

If you're wondering whether your checkout is leaving money on the table, I'd love to take a look. You can book a call here and we'll figure out together whether there's something worth testing.