Not only is this a primarily international board, logistically, following the band around Europe can be percieved as somewhat easier given the size when compared to US and Canada. It's more expensive to cover all the ground spread across the US... that could be a reason. But honestly, there is no way to determine who is the biggest fans. That's fruitless. It has zero to do with how many shows you've seen or if you Deadhead around with the band.