Yeah, it sounds like they were hyped more in Europe - or maybe I just missed the hype here? At any rate I think the HP comparison does a disservice to both series; they're both books about British kids getting involved in a secret magic world, but they're about as different stories as you could tell on that theme. (And I honestly couldn't say which I like better, but I think Artemis Fowl is more consistent, and Artemis himself is way more interesting to me... ^^)