# Mobile sticky button with slide-up buy drawer: +5.2% orders

- Outcome: Won
- Page type: Product page (Ecommerce)
- Elements: Sticky add-to-cart bars, Cart drawers & slide carts
- 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-mobile-slide-up-sticky-atc/

A sticky mobile button that opened the add-to-cart options in a slide-up drawer raised orders by 5.2% for a content-heavy supplement store. GrowthRock ran this A/B/C test and published it on its blog. A second sticky design, which only scrolled shoppers back to the buy area, showed no significant change in orders.

## Result

**+5.2% orders**

- Version C orders: +5.2% at 98% significance.
- Version C add-to-cart clicks: +11.8% at over 99% significance.
- Version B orders: no significant change, even though add-to-cart clicks rose about 6%. Treat B as flat.
- Scale: 14 days, more than 3,000 orders per version.

## Control

The mobile product page had no sticky add-to-cart button. Shoppers had to scroll back to the buy area to purchase.

## Variant

Version C added a sticky button that opened the flavor, quantity and add-to-cart options in a drawer sliding up from the bottom. Version B added a sticky bar that scrolled shoppers back to the buy area on the page.

## Why it likely won (our reading)

- The slide-up drawer may have felt like a focused step of its own, keeping shoppers on the task of buying.
- Scrolling back to the buy area dropped shoppers into the long page again, where they could get distracted.
- With options in a drawer, the page itself may have had more room for persuasive product content.

## Caveats

Mobile only, on the same store as an earlier desktop sticky test. The reasons C beat B are the agency's and readers' reading, not tested facts. The test date was not shared.

## How to run this test

- Hypothesis: If we add a sticky mobile button that opens buying options in a slide-up drawer, then more shoppers will order because they can buy from anywhere on the page without losing their place.
- Primary metric: Orders (conversion rate)
- Guardrail: Add-to-cart rate
- Guardrail: Revenue per visitor
- Guardrail: Product page bounce rate
- Who should test it: Mobile stores with long product pages and options to pick, such as flavor or size. If your buy button is already near the top and pages are short, the gain will likely be smaller. Test the drawer pattern, not just a scroll-to-top bar.

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Credit: GrowthRock ran this test and owns the result. Summary and commentary by LiftArchive (https://liftarchive.com/test/growthrock-supplement-mobile-slide-up-sticky-atc/).
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.