Money-back guarantee under checkout button: +18% revenue per visitor
Test run byDave DiederenSyntra Labs
Commentary byLiftArchiveOur analysis, not theirsAdding a "30 Day Money Back Guarantee" line under the cart's checkout button lifted revenue per visitor by 18% over 30 days. Dave Diederen ran it as a three-way test, and the guarantee line also beat a version with payment icons.
- Revenue per visitor: +18% (£1.76 to £2.07), estimated at about £68,640 more per month.
- Conversion rate: +17% (3.77% to 4.41%), an estimated 1,390 more orders a month.
- Average order value: no change (£46.63 vs £47.03). The gain came from more people checking out.
- A third arm with payment icons under the button also beat control (£1.92 revenue per visitor, 4.22% conversion) but trailed the guarantee.
- Profit per visitor was not available because cost data wasn't entered.
The change
Variant adds a guarantee line under the checkout button
Simplified mockup drawn by LiftArchive from the shared screenshots.
Control
The cart showed the subtotal with the original and sale price, then the Checkout button, with nothing underneath.
Variant
A single line with a checkmark badge reading "30 Day Money Back Guarantee" was added directly under the Checkout button.
Why it likely won
Our reading of the result, not the practitioner's claim.
- the checkout button is where doubts about the purchase peak, so a promise of a refund right there answers them.
- it's a short line that doesn't push the button down or add clutter.
- both reassurance arms beat control, which suggests shoppers in this cart wanted some sign of safety before paying.
Caveats: The test ran for 30 days, but the ranges were wide (-18% to +71% on revenue per visitor), so the true lift could be much smaller. Sample size was not shown.
Who ran it
Dave Diederen (@DaveDiederen) shared this test on X. The numbers and screenshots are theirs.
View the original post on X
How to run this test on your store
- Hypothesis
- If we add a short money-back guarantee line under the checkout button, then more shoppers will check out, because it removes the fear of being stuck with something they don't want.
- Primary metric
- Revenue per visitor
- Guardrails
- Refund rate
- Average order value
- Checkout completion rate
- Who should test it
- Stores that offer a refund guarantee but don't mention it in the cart. It won't help if you can't honour the promise, and it may matter less for low-priced repeat purchases.
Questions
Where should I show my money-back guarantee?
In this test, placing it directly under the cart's checkout button lifted revenue per visitor by 18%.
Is a guarantee better than payment icons under the checkout button?
Here it was. Both beat the control, but the guarantee line earned more per visitor than the payment icons.
Does adding a guarantee raise refunds?
This test didn't report refunds. Track your refund rate after launching, since only conversion and revenue were measured.
Similar tests
@oliverkenyon@DaveDiederen@DaveDiederen@DaveDiederen@DaveDiederen@DaveDiederen