Shorter money-back guarantee copy: +13.08% conversion rate
Test run byDave DiederenSyntra Labs
Commentary byLiftArchiveOur analysis, not theirsShortening the guarantee line on a product page to 'or your money back' lifted conversion rate by 13.08% in Dave Diederen's test. Revenue per visitor rose 11.88% and profit per visitor rose 11.65%. Average order value dipped 1.06%.
- Conversion rate: +13.08% (2.22% to 2.51%), with a 99.6% probability of beating control. The range (+3% to +24%) stays above zero.
- Revenue per visitor: +11.88% ($1.83 to $2.05). Range: -2% to +28%.
- Profit per visitor: +11.65% ($1.20 to $1.34). This was the primary metric in the tool.
- Average order value: -1.06% ($82.20 to $81.32). A slight dip, outweighed by more orders.
- A third version, 'Guarantee V1', was flat to slightly negative (-2.8% conversion). The post does not say what it said.
The change
Same guarantee, shorter copy; badge placement was not shown.
Simplified mockup drawn by LiftArchive from the shared screenshots.
Control
The guarantee promised a noticeable difference within 30 days, with the refund worded as '100% of your money back'.
Variant
The refund wording was cut to 'or your money back'. The 30-day promise itself stayed the same.
Why it likely won
Our reading of the result, not the practitioner's claim.
- shoppers scan badges, and a shorter line is understood at a glance.
- '100% of your money back' can read like small print, which adds a moment of doubt.
- the promise was unchanged, so the gain points to clarity, not a stronger offer.
Caveats: Sample size and test length were not shared. This is a single store, and the copy of the losing third version 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 shorten our guarantee line to 'or your money back', then more shoppers will buy because the promise is quicker to read and feels less like legal copy.
- Primary metric
- Profit per visitor
- Guardrails
- Average order value
- Refund request rate
- Revenue per visitor
- Who should test it
- Stores with a money-back guarantee written in long or legal-sounding language near the buy box. It will not help if you have no guarantee to show.
Questions
How should I word a money-back guarantee?
Keep it short. In this test, 'or your money back' beat a longer '100% of your money back' line by 13.08% on conversion.
Does guarantee wording really affect conversion?
Here it did, with a 99.6% probability of beating control. The promise was the same; only the wording changed.
Did the shorter guarantee affect refunds or order value?
Refunds were not reported. Average order value dipped 1.06%, but revenue and profit per visitor still rose.
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