That's not what a klarna transaction is. Klarna pays the vendor immediately (with its credit line), and the user enters into a sort of debt contract with klarn

That's not what a klarna transaction is. Klarna pays the vendor immediately (with its credit line), and the user enters into a sort of debt contract with klarna. Klarna's revenue is what it receives from the user. It's a great business model when the interest rate is 0%.