It's not just Sarah Palin. Even more people seem to think that Africa is a country and not a continent. I bought some cashew nuts today and after I got them home I noticed that the distributor labelled them as coming from Africa, Brazil and/or India. Brazil and India are both countries while Africa is a continent.
While you could legitimately argue that islands off the continental mainland, such as Cape Verde, aren't African countries there's no denying that
Africa has over 50 countries. As such, labelling a product as coming from Africa is only slightly more useful than labelling it as coming from Earth.
You have to wonder why the distributors haven't named the country from where the nuts come. It's probably Nigeria, Côte d'Ivoire, Tanzania, Guinea-Bissau or Mozambique as they are the African countries that produce the most cashew nuts. I'm not aware of anything about any of these countries that would act as a disincentive to cashew buyers if they knew that those countries were the source of their nuts.
So maybe Sarah Palin has a second job designing product labels for the Hershey Import Co. Inc?