Recruit a friend, in Denmark

Hello, I have a friend that wants me to switch to his Euro server. In order to do that i would need to make a new account and start from scratch, i wouldn't want to do this without the recruit a friend option to gain the bonus experience so i could level up faster. He says that in certain countries it doesn't work. Is this really true? Because it doesn't make sense that it wouldn't. He lives in Denmark and he said he couldn't get the recruit a friend option to work. What is the problem here? And why would Blizzard limit certain countries to recruit a friend?? Any help would be great, thanks.