Cool song. I think it's refreshing as well. Not that I think the song can't stand on its own, but man, that smart and quirky video definitely helps bump up its popularity. I guess it just goes to show, sometimes song writing rules are meant to be broken.
It's all about the arrangement, in my opinion; the parts fit together like a brilliant little jigsaw puzzle, and that's why the Walk Off The Earth version works so well. The whole thing could have been multitracked with a single guitar and overdubbed vocals; in fact, I'd be surprised if the original demo wasn't, heh. The intro's engaging, a bit mysterious; it draws you in and the arrangement slowly but steadily builds to quite a climax, even if it does come along well into the song. And yes, it's loaded with hooks.
The licensing is most likely a series of single-song publishing/distribution deals for each country, which is entirely do-able if you don't have a traditional multi-album record contract.