Conversion rate measures the percentage of visitors who complete a target action. For ecommerce, this typically means the percentage of sessions that result in a purchase (purchase conversion rate). It's calculated as: (Number of Conversions / Total Visitors) × 100.
Ecommerce conversion rates vary dramatically by industry, traffic source, and device. Average rates hover around 2-3%, meaning 97-98% of visitors leave without buying. High-performing stores might achieve 5-8%, while cold traffic campaigns may convert below 1%.
Improving conversion rate is one of the highest-leverage activities in ecommerce because it multiplies the value of all traffic. A site converting at 2% vs 3% sees 50% more revenue from the same traffic. Testing product pages, checkout flow, pricing presentation, and trust signals can systematically improve conversion.