# Sticky buy box on desktop product pages: +7.9% orders

- Outcome: Won
- Page type: Product page (Ecommerce)
- Elements: Sticky add-to-cart bars
- Test run by: [GrowthRock](https://liftarchive.com/practitioners/growthrock/)
- Commentary by: LiftArchive (our analysis, not theirs)
- Original source: https://growthrock.co/sticky-add-to-cart-button-example/
- Page: https://liftarchive.com/test/growthrock-supplement-sticky-buy-box-desktop/

Keeping the whole add-to-cart area fixed on screen while shoppers scrolled raised orders by 7.9% on desktop product pages for a content-heavy supplement store. GrowthRock ran this A/B test and published it on its blog. The store already used the sticky version, so the test checked whether to keep it.

## Result

**+7.9% orders**

- Orders: +7.9% at 99% significance.
- Add-to-carts: +8.6% at 99% or higher significance, and the extra adds turned into orders.
- Scale: 14 days, about 2,000 orders per version.

## Control

The buy box sat in one place on the desktop product page and scrolled out of view as shoppers read further down.

## Variant

The entire add-to-cart area stayed fixed on the right side of the page while shoppers scrolled. Product name, images, price and button text were the same in both versions.

## Why it likely won (our reading)

- Shoppers who read long product content could buy at any point without scrolling back up.
- The fear that a sticky box would feel pushy to readers did not show up in the numbers.
- A constant buy option is a quiet reminder that the page is there to sell.

## Caveats

The live site already had the sticky buy box, so this test measured what removing it would cost. Desktop only, and the test date was not shared.

## How to run this test

- Hypothesis: If we keep the add-to-cart area fixed on screen while shoppers scroll a long product page, then more will order because they can act the moment they are convinced.
- Primary metric: Orders (conversion rate)
- Guardrail: Add-to-cart rate
- Guardrail: Revenue per visitor
- Guardrail: Cart abandonment rate
- Who should test it: Stores with long, content-heavy product pages on desktop, such as supplements or technical products. It matters less if your product pages are short and the buy button is always in view.

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Credit: GrowthRock ran this test and owns the result. Summary and commentary by LiftArchive (https://liftarchive.com/test/growthrock-supplement-sticky-buy-box-desktop/).
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.