Cookie duration can really impact how well an affiliate program works. It's basically how long a link stays "active" after someone clicks it. If the cookie lasts longer—like 30 or 90 days—there's a better chance the affiliate gets credit for the sale, especially if the customer takes time to decide. Short cookies, like 24 hours, might work for quick buys, but they can cheat affiliates out of commissions if people wait before buying. Longer durations make affiliates feel more valued and willing to promote. Still, businesses have to balance that with the costs. In the end, the best cookie length depends on what you're selling and how your customers shop—but it definitely matters.