What We Measure
We build the proof in GA4 around the discovery sequence: view_item_list → select_item → view_item → add_to_cart. That lets us separate a category or search problem from a product-page persuasion problem. We track session-based add-to-cart rate as the core product-page metric, a healthy operating range is roughly 5–10% globally, though category mix matters, alongside list-to-product click-through, search usage and search conversion, and the variant-selection completion rate. Because many product-page changes work by reducing doubt before the add event moves, we also watch gallery, review and mini-cart interaction, and we benchmark each store against its own device, category and traffic-source medians rather than a single universal number.