Pie charts and area charts can work well when there are two, three, four different data choices. Once you start to get above that, you can end up with tons of teeny slices like this, where it isn't possible to make a reasonable comparison between any two slices without having to look at the numbers.

One thing you could do is group them together into larger slices, so that all of the North America slices are the same general color and grouped together (maybe US a slight different shade of the same color from Canada), and group all of Europe together, etc. That way it doesn't end up looking like someone spilled a big box of crayons on the floor, and the colors have meaning.