It's an awesome common that's powered by having certain lands in play - and [card]Mountain[/card] and [card]Plains[/card] aren't all that hard to get into play nowadays with [card]Terramorphic Expanse[/card] and [card]Naya Panorama[/card] around.
You see it in nearly every iteration of Extended and Standard Zoo now - all this and it's a simple common!