Fees and commissions on ecommerce marketplaces vary widely. Typically, platforms charge a percentage of each sale, known as a commission, ranging from 5% to 20%. Some marketplaces also impose listing fees, transaction fees, and payment processing fees. For example, Amazon charges a referral fee and a variable closing fee, while Etsy has listing fees and transaction fees. Always review the specific fee details of each platform to ensure you account for all costs in your pricing strategy.