Sticky Add-to-cart Tests on Product Pages: 8 Examples, 3 Results

Why sticky add-to-cart matters on the product page

Product pages are long, especially on mobile. Once a shopper scrolls past the buy box into reviews, images and FAQs, the button is gone.

A sticky bar keeps the next step one tap away wherever they are on the page.

The catch is variants and bundles. If the bar adds to cart without a size, colour or pack choice, shoppers can end up with the wrong item.

Both of Dave Diederen's tests handled this by sending people back up to the selector.

Measured results

Sticky bars that return to the buy box

Dave Diederen added a sticky add-to-cart bar that scrolls back to the main buy box: +11.67% conversion rate, +17.39% revenue per visitor and +5.12% AOV.

Revenue per visitor rose faster than conversion rate, so the extra orders were also slightly larger.

A second Dave Diederen test scrolled to the top only when variants or bundles had to be picked and won +$32,565/month in revenue. No conversion rate figure was given.

Sticky add-to-cart as part of a bigger change

Oliver Kenyon added a rating under the title, moved the discount badge next to the ATC, added a sticky ATC and made thumbnails clickable.

It won +$38,846/month, forecast at +$466,152/year. Four changes shipped together, so the sticky bar's share is unknown.

A

→

B

+$38,846 per month

Added rating under title, moved discount badge by ATC, sticky ATC, clickable thumbnails

Product pageReviews & star ratings@oliverkenyon

A

→

B

+$32,565/month revenue

Added a sticky add-to-cart bar (scrolls to top when variants or bundles must be picked)

Product pageBundles & quantity breaks@DaveDiederen

A

→

B

+17.39% revenue per visitor

Added a sticky add-to-cart bar that scrolls back to the main buy box

Product pageSticky add-to-cart bars@DaveDiederen

Losing or flat tests

None are listed. That may reflect which results get shared as much as how sticky bars perform, so it is worth running your own test rather than assuming a win.

Untested ideas

• A sticky bar that adapts to variants: single-SKU products add to cart straight from the bar, products with variants scroll back to the selector or show selectors inside the bar (Dave Diederen).
• A sticky bar with review stars, price and discount, an action CTA such as "Grab yours" and the selected variant's image (Kasper Dolk).
• A sticky CTA so visitors can buy without scrolling back (Dave Diederen).

Josh Thompson reports +17% and +12% checkout rate from a sticky and a floating add-to-cart button, but no test data is shown, so treat those as claims.

Placement and design patterns that won

• Use the bar to return shoppers to the buy box when a choice is needed.
• Judge the test on revenue per visitor as well as conversion rate.

Related tests elsewhere on the store

See the full sticky add-to-cart collection, product page add-to-cart button tests and add-to-cart buttons across the store.