Genius and Pandora are quite different. They have some overlap in functionality, but at it's core Genius is about the music you already know and have. It's more about solving the paradox of choice that occurs when you have a large music library than it is a recommendation and discovery engine.
It sucks to live outside the US. I could probably access Pandora through a proxy (I haven't tried), but it's a barrier, and even one complication makes a lot of people not do something (look at sites where you can comment anonymously versus sites that make you create an account just to comment on a story).
