I'm really starting to question this whole "new players -> play with their friends" line of thinking. I'm certain that we can find some sort of trend via the referral system, but I would bet that most new players would play regardless of having friends in the game or not.... so I'm starting to have a suspicion this isn't a very good argument to having the jump potions. You could simply modify the referral program to allow XP boost gear that's valid to 60, and some sort of bonus/juicy incentive (not just the meh choco feathers or glamours) for a current player to go and play the old stuff with a friend they referred. At least in this case they're being mentored through the early game by a current player.