# Low-stock announcement bar on product pages: -17.5% conversion rate

- Outcome: Lost
- Page type: Product page (Ecommerce)
- Elements: Low-stock & scarcity messaging, Announcement bars
- Test run by: [Clean Commit](https://liftarchive.com/practitioners/clean-commit/)
- Commentary by: LiftArchive (our analysis, not theirs)
- Original source: https://cleancommit.io/ab-tests/low-stock-announcement-bar-added-to-product-pages/
- Page: https://liftarchive.com/test/cc-low-stock-announcement-bar-added-to-product-pages/

Adding an announcement bar that warned stock was running low cut conversion rate by 17.5% and orders by 18.5%. Clean Commit ran this test for an anonymized Shopify store and published it in its A/B test library. The original had a 93.8% probability of doing better after 6 days.

## Result

**-17.5% conversion rate**

- Conversion rate: -17.5%, a clear negative result. The original had a 93.8% probability of being better.
- Orders: -18.5%.
- Revenue per visitor: -11.3%, a smaller drop because average order value rose 7.4%.
- Conversion rate fell on both mobile and desktop.

## Control

Product pages showed no message about stock levels.

## Variant

A prominent announcement bar on product pages told shoppers stock was low. It was designed to stand out on mobile.

## Why it likely lost (our reading)

- A generic stock warning can read as a sales trick and lower trust.
- Shoppers may worry their size or color is gone and leave instead of checking.
- A loud bar at the top pulls attention from the product and the buy button.

## Caveats

Small, short test: 5,161 visitors over 6 days. The direction held on both devices, but the size of the drop is uncertain.

## How to run this test

- Hypothesis: If we show a low-stock announcement bar on product pages, then conversion rate will rise because shoppers feel urgency to buy before items sell out.
- Primary metric: Conversion rate
- Guardrail: Orders
- Guardrail: Revenue per visitor
- Guardrail: Bounce rate
- Who should test it: Stores with real, product-level stock limits, such as small-batch drops. If stock is not actually low, or the message is the same on every product, expect it to hurt trust.

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Credit: Clean Commit ran this test and owns the result. Summary and commentary by LiftArchive (https://liftarchive.com/test/cc-low-stock-announcement-bar-added-to-product-pages/).
Usage: Free to use, quote and build on, with credit and a link: name the practitioner or organization that ran the test and link to its LiftArchive page. The results belong to the practitioners who ran and shared them; the summaries and commentary are LiftArchive's.