Does a sticky add to cart bar lift mobile product page sales?
On mobile, the add to cart button scrolled out of view as shoppers read down the product page. We tested 2 sticky add to cart bars. The simple bar lifted conversion rate 7.0% on mobile over 15 days.
Won Mobile 15 days Called at 90%
The hypothesis
By keeping an add to cart button on screen after the main button scrolls away, we will make it easier to buy at any point, resulting in a higher conversion rate.
A sticky button stays visible as shoppers scroll. When the button is always in reach, shoppers are more likely to notice it and use it.
We tested 2 versions to see whether extra detail in the bar would help: a plain add to cart button, and the same button with the product name and star rating.
What we changed
We added a sticky add to cart bar once the main button left the screen.
Both variations added a bar that stayed on screen and appeared only after the main add to cart button scrolled out of view. Var A showed a simple add to cart button. Var B added the product name and star rating next to the button. The test ran on mobile and desktop.
- Add to cart bar stays on screen on scroll
- Appears after the main button leaves view
- Same sticky add to cart bar as Var A
- Adds the product name to the bar
- Adds the star rating to the bar
The result
The simple sticky bar lifted mobile conversion rate 7.0%.
On mobile, Var A, the simple bar, lifted conversion rate 7.0% and revenue per visitor 12.0% over 15 days. We chose Var A to implement across all mobile product pages. Desktop did not see the same lift, which we expected because sticky buttons are less common on desktop, so we paused the desktop side.
What we took from it
On mobile, a plain buy button kept in reach was enough.
Long mobile product pages push the main button off screen quickly. A simple bar that brings it back closed that gap. The product name and rating in Var B did not add enough to beat the plain button. On desktop the main button stays in view longer and sticky bars are less expected, so the change mattered less there.