To identify underperforming products faster on Shopify, you need to track leading indicators (conversion rate decline, rising return rate, slowing sell-through velocity relative to inventory position) rather than waiting for a lagging indicator like monthly revenue to confirm a problem that has already been building for weeks. Most Shopify brands discover an underperforming product during a routine sales review, by which point the product has typically been quietly losing money or tying up cash in unsold inventory for one to three months. This post covers the specific signals that show up early, how to monitor them without manual weekly review, and how the detection timeline has changed as ecommerce analytics has moved from quarterly spreadsheets to continuous monitoring.