Sunless Tanning -- Let's Talk Girls

So I understand from friends, Estee Lauder's Sunless Tanning with Tint is the way to go. The tint means when you put it on, you can SEE WHERE YOU PUT IT. Some of the untinted creams lead you to paint yourself here, there but not everywhere and can have some unusual effects. You need to exfoliate first -- a loofa will do. And then as the woman in this site says, "blend, blend, blend." She begins: "I am corpse white as my husband so charmingly points out and I simply don't tan so I tried this "self-tanner" by Estee Lauder in Medium over the weekend ...

Four hours later, you're tan. But I don't get it, how long are you tan for? Four hours? Four days? Four weeks? Nine and 1/2 weeks?