Persistent Add to Cart
Overview
Mobile PDPs require users to scroll through large amounts of content (images, specs, reviews), often pushing the Add to Cart CTA out of view. This creates friction at a critical decision point.
Hypothesis
If we make the add to cart CTA sticky on mobile PDPs, then customers will be more likely to add products to cart because the ability to do so will be a consistent primary action on the page as they scroll through the content.
Test Duration
January 24, 2024 – February 25, 2024
Role
UX/UI Designer
Collaborators
CRO Specialist
Developer
Stakeholders
WHY?
Data was showing high content engagement on PDPs. I hypothesized scrolling back to add to cart was introducing unnecessary friction.
TEST DESIGN
What We Tested
- Devices: Mobile + Desktop PDPs
- Control: Standard PDP with non-sticky Add to Cart CTA
- Challenger: Sticky Add to Cart CTA that remains visible during scroll
KEY INSIGHT
Persistent Actions Drive Engagement
Persistent CTAs can meaningfully improve engagement-level conversion signals such as ATC and wishlist.
KEY INSIGHT
Intent Doesn't Ensure Conversion
Increased intent does not guarantee downstream conversion when checkout friction remains unresolved, added that the PDP is far removed from the checkout funnel.
KEY INSIGHT
Wishlist Indicates Delayed Intent
Increased wishlist behavior may indicate delayed purchase intent, but not lost conversion. This is also reinforces furniture purchase cycles and behavior.
IMPACT
The Results
+6%
lift in add to cart clicks at 95% confidence
+48%
lift in wishlist clicks at 95% confidence
+$141k
incremental revenue if test had been rolled out to 100% of traffic during test period
© 2026 Noah Heuton