GMV is computed as the sum of gross order values across a period — equivalently, AOV × order count. Refunds, discounts, cancellations, shipping, taxes, and platform fees all sit above the line. That is the definition’s whole point: GMV measures transaction volume routed through the storefront, not what the business kept.
The same period can produce three materially different GMV numbers depending on who reports it. Marketplace-reported GMV (Amazon, eBay, Etsy) counts every transaction routed through the platform, gross of returns and fees. Shopify-reported “gross sales” is the storefront’s gross orders before refunds and discounts. Accounting-reported GMV is sometimes restated net of cancellations or post-period adjustments — convention varies by finance team. Same period, three numbers; the gap is a definitional choice, not noise.
GMV is the most-cited top-line ecommerce number because it is the largest, cleanest, most bullish figure available — which is exactly why it leads boards and investor decks. It also overstates economic reality: it includes revenue the brand will never collect (refunds, chargebacks, cancellations) and, on marketplaces, revenue the brand never owned (platform take rates and payment processing strip out a meaningful share before the seller sees a dollar).
Three layers, not one: GMV → net revenue (after refunds and discounts) → recognized revenue (the P&L figure, after marketplace fees, payment processing, and deferred-liability treatments like gift cards). An operator reading an investor deck should ask which version is cited and how it reconciles to the number that ultimately funds contribution margin.