Experiments

FLOATING ADD-TO-CART BUTTON

Floating Add-to-Cart Button

The Experiment in Action

Hypothesis

On the product display page (PDP), the add-to-cart button reminds shoppers to add items to their cart and can help them to complete their purchase.

On mobile, a static add-to-cart button can be easily missed. Therefore, the addition of a floating add-to-cart button could increase Cart Rate* and Revenue per Visitor (RPV).

*Cart rate is defined as the percentage of all visitors that add at least one product to their cart.

CONTROL – MOBILE

Floating Add-to-Cart Button - Control

TREATMENT – MOBILE

Floating Add-to-Cart Button - Treatment

Floating Add-to-Cart Button Experiment

How It Works

How It Works

This mobile-only experiment adds a floating add-to-cart button to the bottom of the mobile screen. This button remains at the bottom of the screen as the user scrolls up and down the page.

The add-to-cart button is configured to fade out when the existing, static add-to-cart button is visible.

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Why We Are Testing It

On mobile, a static add-to-cart button can be easily missed. Sometimes it is located too high on the page and the user loses sight of it as they scroll to the product details. Other times, it is too low on the page, reducing the urgency to complete the add-to-cart action.

This experiment seeks to determine whether a floating add-to-cart button helps to expedite users from the window shopper stage to the shopper stage of the checkout funnel.

Results: Floating Add-to-Cart Button Experiment

Average performance numbers are based on results from April 13, 2018 to September 15, 2019 from 20 merchant sites.

Average Experiment Results So Far*

Device TypeAverage LiftVisitors
Revenue per Visitor
(RPV)
Conversion Rate
(CR)
Average Order Value
(AOV)
TreatmentControl
Device Type: MobileMobile
+0.71%+0.80%+0.06%2,577,3272,371,707

Results: Floating Add-to-Cart Button Experiment

Average performance numbers are based on results from April 13, 2018 to September 15, 2019 from 20 merchant sites.

Average Experiment Results So Far*

Device Type: MobileMobile
Average Lift
Revenue per Visitor
(RPV)
Conversion Rate
(CR)
Average Order Value
(AOV)
-0.71%+0.80%+0.06%

Visitors: Treatment: 2,577,327 | Control: 2,371,707

Distribution of Average RPV Lift
for All Visitors

Distribution of Average RPV Lift - Floating Add to Cart RPV

The RPV distribution shows a mixed reaction to this experiment with almost as many visits registering negative RPV lift as those showing positive lift.

Distribution of Average Cart Rate
for All Visitors

Distribution of Average RPV Lift - Floating Add to Cart Cart Rate

The cart rate distribution indicates that the treatment encouraged more add-to-cart actions. Deeper analysis may uncover why this is not translating to greater lifts in RPV.

*These results reflect the average findings for all participating merchants and are not guaranteed for all users.

Data Analysis: Floating Add-to-Cart Button Experiment

What It Means

What It Means

The RPV lift for the floating add-to-cart button experiment was insignificant (+0.71%). However, 92% of merchants experienced a positive lift in cart rate. This indicates that the treatment is successful in stimulating the immediate add-to-cart action, but mixed in terms of stimulating RPV lift.

To better understand this, we segmented the data by four add-to-cart transition behaviors (i.e. what happens after the add-to-cart button is clicked) used across the merchants’ sites. We found that some of these behaviors are more compatible with the add-to-cart button than others. For example, merchants that serve a standalone popup modal after users add items to their cart perform the worst. This could be due to user frustration from an abundance of floating elements on the screen.

Average Experiment Results of
Post Add-to-Cart Transitions

Add-to-Cart TransitionVisitorsAverage Lift
TreatmentControlRevenue per Visitor
(RPV)
Conversion Rate
(CR)
Average Order Value
(AOV)
Total2,577,3272,371,707+0.71%+0.80%+0.06%
Standalone Pop Up Modal
(8 merchants)
1,005,6811,012,191-4.01%-4.57%+0.65%
Same-Page Reload + Success Message
(5 merchants)
447,622405,021+0.86%+7.15%-5.74%
Pop Up Minicart
(3 merchants)
169,407175,152+9.54%+4.03%+5.14%
Send Directly to Cart
(4 merchants)
954,617779,343+3.98%+3.22%+1.00%

Things to Consider

Merchants should consider the behavior of their average shoppers by testing optimizations that streamline the journey along the conversion funnel. The floating add-to-cart button could usher shoppers along the conversion funnel and move them from the window shopper stage to the shopper stage. By experimenting with combinations of optimizations — like a floating add-to-cart button with a pop up minicart transition — merchants could effectively increase conversion rates along the checkout funnel. Experimenting with optimizations throughout the funnel could have a compounding effect in increasing total revenue.

Data Analysis: Floating Add-to-Cart Button Experiment

What It Means

What It Means

The RPV lift for the floating add-to-cart button experiment was insignificant (+0.71%). However, 92% of merchants experienced a positive lift in cart rate. This indicates that the treatment is successful in stimulating the immediate add-to-cart action, but mixed in terms of stimulating RPV lift.

To better understand this, we segmented the data by four add-to-cart transition behaviors (i.e. what happens after the add-to-cart button is clicked) used across the merchants’ sites. We found that some of these behaviors are more compatible with the add-to-cart button than others. For example, merchants that serve a standalone popup modal after users add items to their cart perform the worst. This could be due to user frustration from an abundance of floating elements on the screen.

Average Experiment Results of
Post Add-to-Cart Transitions

Add-to-Cart Transition

Average Lift
Revenue per Visitor
(RPV)
Conversion Rate
(CR)
Average Order Value
(AOV)
+0.71%+0.80%+0.06%

Total Visitors: Treatment: 2,577,327 | Control: 2,371,707

Standalone Pop Up Modal
(8 merchants)

Average Lift
Revenue per Visitor
(RPV)
Conversion Rate
(CR)
Average Order Value
(AOV)
-4.01%-4.57%+0.65%

Visitors: Treatment: 1,005,681 | Control: 1,012,191

Same-Page Reload + Success Message
(5 merchants)

Average Lift
Revenue per Visitor
(RPV)
Conversion Rate
(CR)
Average Order Value
(AOV)
+0.86%+7.15%-5.74%

Visitors: Treatment: 447,622 | Control: 405,021

Pop Up Minicart
(3 merchants)

Average Lift
Revenue per Visitor
(RPV)
Conversion Rate
(CR)
Average Order Value
(AOV)
+9.54%+4.03%+5.14%

Visitors: Treatment: 169,407 | Control: 175,152

Send Directly to Cart
(4 merchants)

Average Lift
Revenue per Visitor
(RPV)
Conversion Rate
(CR)
Average Order Value
(AOV)
+3.98%+3.22%+1.00%

Visitors: Treatment: 954,617 | Control: 779,343

Things to Consider

Merchants should consider the behavior of their average shoppers by testing optimizations that streamline the journey along the conversion funnel. The floating add-to-cart button could usher shoppers along the conversion funnel and move them from the window shopper stage to the shopper stage. By experimenting with combinations of optimizations — like a floating add-to-cart button with a pop up minicart transition — merchants could effectively increase conversion rates along the checkout funnel. Experimenting with optimizations throughout the funnel could have a compounding effect in increasing total revenue.

Who Should Try It

In isolation, the floating add-to-cart button alone may not have an immediate positive impact. However, testing the floating add-to-cart button in conjunction with optimized post add-to-cart transitions could have greater impact on RPV.

Merchants that already optimize add-to-cart transition behaviors are likely to succeed with the floating add-to-cart button experiment. Merchants that utilize a standalone pop up modal should still consider this experiment, since every shop is different and other unknown factors may still help to achieve better results.

Who Should Try It

In isolation, the floating add-to-cart button may not have an immediate positive impact. However, testing the floating add-to-cart button in conjunction with optimized post add-to-cart transitions can have greater impact on RPV.

Merchants that already optimized add-to-cart transition behaviors are likely to succeed with the floating add-to-cart button experiment. Merchants that utilize a standalone pop up modal should still consider this experiment, since every shop is different and other unknown factors may still help achieve to success.

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