Ali Demirbaş - Lab
TRGet in touch

Category & Listing

Marking Already-Viewed Products A/B Test Example

A small “Viewed” label may help shoppers keep their place in a long list.

  • Category listing
  • Purchase conversion rate

Control vs Variant

Absent on one side, present on the other.

Changed
Presence
Page
Category listing
Difference
added

Hypothesis

It could also make a product seem ruled out and reduce reconsideration. Judge the result by purchases and use browsing behavior for context.

How to run this test

Primary metric

Purchase conversion rate

Compare purchases among all eligible assigned visitors; do not limit the analysis to visitors who clicked a product marked “Viewed.”

Other metrics

  • Unique products viewedCheck whether visitors view a wider range of products.
  • Repeat product viewsTrack whether visitors reopen the same product.
  • Return visits to a productSeparate later visits from immediate repeat views; fewer returns are not automatically better.
  • Time in listingMake sure browsing time does not increase unreasonably.

What to check before and during the test

  • LabelAdd a small “Viewed” label to a product card after the product page has been opened.
  • Keep constantKeep sorting, card styling and eligible products unchanged.
  • History windowPredefine and keep the history window and reset rule fixed.
  • ReconsiderationCheck whether visitors revisit and purchase products marked as viewed.
  • Separate testsDo not include dimming the card, changing the reset period or removing the product from the list.

Setup mistakes to avoid

  1. 1Do not fade the label or card until the product is hard to read.
  2. 2Do not change the viewed marker and product sorting together.
  3. 3If history persists across sessions, explain that clearly to visitors.
  4. 4Do not remove viewed products from the list in this test; that is a separate variable.
  5. 5Do not generalize a result from a short list to very long lists.