Selling Out Fast banner with progress bar: +8.04% conversion
Test run byDave DiederenSyntra Labs
Commentary byLiftArchiveOur analysis, not theirsAdding a "Selling Out Fast" banner with a percent-sold progress bar and a countdown to a product page raised conversion rate by 8.04% in a test Dave Diederen ran. Revenue per visitor rose 8.83% and average order value did not change.
- Conversion rate: +8.04% (2.04% to 2.21%). More visitors bought. The range shown is -4% to +22%, so the lift is likely but not certain.
- Revenue per visitor: +8.83% ($0.95 to $1.03). The range of -8% to +29% is wide.
- Average order value: no change ($46.35 vs $46.69). The gain came from more orders.
- Estimated impact in the testing tool: about 508 more orders and $25,856 more revenue a month.
The change
The variant adds a scarcity banner with a sold bar and countdown below the add-to-cart button.
Simplified mockup drawn by LiftArchive from the shared screenshots.
Control
The product page without a scarcity section below the add-to-cart button.
Variant
A banner under the add-to-cart area reading "Selling out fast" with a short line about limited stock, a progress bar showing 89% sold, and an "Ends in" countdown.
Why it likely won
Our reading of the result, not the practitioner's claim.
- many visitors plan to come back later and never do. The banner gives them a reason to act today.
- a progress bar and a specific "89% sold" figure make limited stock feel concrete, unlike a generic badge.
- the countdown adds a clear time limit, and the low price point (about $46 per order) suits a quick decision.
Caveats: The screenshot of the page uses another brand as a visual example, so it may not be the store tested. Sample size and test length were not shared, and both ranges include a small loss.
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 scarcity banner with a percent-sold bar and countdown near the add-to-cart button, then more visitors will buy now because waiting feels costly.
- Primary metric
- Conversion rate
- Guardrails
- Revenue per visitor
- Return visitor conversion rate
- Customer complaints about fake urgency
- Who should test it
- Stores selling low-consideration products with real limited stock or genuine drops. It probably will not help expensive or complex purchases, and fake numbers that never change can damage trust.
Questions
Do scarcity banners increase conversions?
In this test a "Selling out fast" banner lifted conversion 8.04% and revenue per visitor 8.83%, with order value flat.
Is a percent-sold progress bar better than a low-stock badge?
This test did not compare them. Dave Diederen argues a specific figure like 89% sold feels more concrete than a generic badge.
Can fake scarcity backfire?
Diederen warns it can. If every product is always 89% sold or the timer resets on refresh, visitors may spot it and trust the store less.
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