I don't think they should plan on too many premium subscriptions in the U.S., Napster does this now, and they even recently went to $5 a month, and you don't hear too much about them. I think anything "youth-oriented" (music, Facebook) will need to live or die on ads because the kids don't have credit cards and don't want to ask their parents to pay for this, especially if the parents know they can "get it for free".