If a feedback pop-up appeared right after a user abandoned checkout, the single question it should ask is: "What stopped you from completing your purchase today at all?" It invites reasons like price, delivery, payment issues, or just distraction. Because it's immediate, the user still remembers context, making responses more accurate. Short wording reduces friction, so people are more likely to answer. Aggregating replies helps identify patterns in drop-offs, similar to funnel analytics, but in the user's own words.