# Sticky add to cart with swatches and bottom placement: inconclusive

- Outcome: Flat / inconclusive
- Page type: Product page (Ecommerce)
- Elements: Sticky add-to-cart bars, Variant, size & option selectors
- Test run by: [Blend Commerce](https://liftarchive.com/practitioners/blend-commerce/)
- Commentary by: LiftArchive (our analysis, not theirs)
- Original source: https://blendcommerce.com/blogs/ab-tests-shopify/better-placed-sticky-add-to-cart-product-page-conversion
- Page: https://liftarchive.com/test/little-bible-stories-sticky-atc-swatches/

Adding colour swatches to the desktop sticky add-to-cart bar and moving the mobile sticky button to the bottom of the screen lifted conversion rate by 7% for Little Bible Stories, but we count the result as inconclusive. Blend Commerce ran this A/B/C test on product pages, and the gain was not statistically significant. Revenue per visitor stayed flat and fell 18% on mobile.

## Result

**inconclusive**

- Conversion rate: +7%, but not statistically significant.
- Add-to-cart rate: +8%, and sticky add-to-cart clicks: +27%.
- Revenue per visitor: flat overall, so more orders did not mean more revenue.
- Mobile revenue per visitor: -18%. Desktop conversion: -5%, despite 148% more sticky clicks. Device splits were not significant either.

## Control

The existing sticky add-to-cart used a text dropdown for colour on desktop and only became useful on mobile after shoppers scrolled through the product content.

## Variant

Variant 2 showed visual colour swatches in the desktop sticky bar and pinned the mobile sticky button to the bottom of the screen. A third arm (Variant 1) used the same swatches but put the mobile button at the top.

## Why it likely came out this way (our reading)

- Swatches show options at a glance, so more shoppers clicked the sticky bar. That did not carry through to revenue.
- A bottom-of-screen button is easier to reach with one thumb, which may explain the mobile engagement gain.
- Mixed results across devices and flat revenue suggest the changes moved clicks more than purchases. The agency planned a follow-up test on the mobile revenue drop.

## Caveats

This was an A/B/C test, and neither the overall nor the device-level results were statistically significant, so we treat it as inconclusive. The agency still rolled out Variant 2. Sample size and test length were not shared.

## How to run this test

- Hypothesis: If we show visual swatches in the sticky add-to-cart bar and pin it to the bottom of the mobile screen, then more shoppers will add to cart and buy because options are clearer and the button is easier to reach.
- Primary metric: Conversion rate
- Guardrail: Revenue per visitor, split by device
- Guardrail: Average order value
- Guardrail: Add-to-cart rate
- Who should test it: Stores with products in several colours or styles that already use a sticky add-to-cart. Plan for enough traffic to reach significance per device; small stores may struggle to get a clear answer from a three-way test.

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Credit: Blend Commerce ran this test and owns the result. Summary and commentary by LiftArchive (https://liftarchive.com/test/little-bible-stories-sticky-atc-swatches/).
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.