Graying Out vs Hiding Out-of-Stock Products A/B Test

Category-page purchase rate

Compare purchases among category visitors assigned to the two out-of-stock display approaches.

• Product detail click-through rateCompare visits to in-stock product pages between arms.
• Category-page exit rateTrack exits among visitors who see the category page.
• Back-in-stock signup rateTrack this only if a “notify me” flow already exists; do not add a new signup flow.
• Listing load timeCheck whether stock-status and label handling affects load time.

• DisplayShow the same out-of-stock products in gray in one arm and hidden in the other.
• Keep constantKeep the order, filters and stock data for available products the same.
• PurchasesCompare purchases among all eligible visitors assigned to the category-page experience.
• Out-of-stock shareRecord the share of products out of stock; eligibility should be comparable between arms.
• Existing flowIf a back-in-stock notification already exists, keep it the same in both arms.

1. 1Do not change sorting along with gray styling.
2. 2Do not make unavailable products appear purchasable.
3. 3Track the effect of hiding products on category browsing.
4. 4Do not interpret results if stock levels are unbalanced across arms.
5. 5Do not switch on a “show in-stock only” filter without the visitor's choice.