Buy box
The buy box is the section of a marketplace product page — such as the 'Add to cart' block on Amazon or the koopblok on bol — where the marketplace designates one default seller from all sellers offering that same product. On marketplaces where multiple sellers share a single product listing, the buy box decides which seller gets the order when a customer simply clicks the buy button; the other sellers are tucked away behind an extra click.
How the buy box is won
Marketplaces do not publish an exact formula, but consistently name the same factors: total price (product plus shipping), delivery speed and availability, and seller performance metrics such as cancellations, returns and customer satisfaction. Price is a heavily weighted factor a seller can adjust from one minute to the next — which is exactly why the buy box and automated repricing are so tightly linked.
Why it creates price pressure
Because most orders on a shared listing flow through the buy box, losing it means losing most of the sales for that product. Sellers therefore compete on the fastest-moving factor — price — often with repricers undercutting each other automatically. For brands this matters too: buy-box competition between their own resellers is a common route to price erosion and prices sliding below the recommended level.
How PricePatrol fits in
PricePatrol tracks the price actually shown on a product page over time — on marketplaces and regular shops alike — so sellers and brands can see how buy-box competition moves street prices, per product and per country.