Amazon Cookie 90 days using add to cart? How

Does anyone know how to get the 90 day amazon cookies? is this possible?

30 seconds search on google: "If ANY customer visits Amazon through ANY special link and adds a product to their cart, you get an 89 day extension. This means that the normal Amazon links you are already using can still earn you a 90 day cookie, and you’ve likely already had it happen."

Basically you don't need to do anything else. Reference.