Until we get the client updated with some further information on this concept, we've noted some confusion (rightfully so) on the whole concept of who gets IP or how they get IP when someone is invited to the game via the Master/Apprentice system.
Let me do my best to clarify this for you.
If you invite someone to the game using a "Recruit a Friend" Invitation on the homepage, and they create a new account with the Invite code they were given then purchase LP, you will receive 2 IP for every 1 LP they purchase.
It is not tied to the Universal Invite Code, nor with the Master/Apprentice system that is on the same screen as your "Recruit a Friend" invitations. They are exclusive from each other.
You MUST be sending it to someone who creates the account with the invite code sent to them from your invitation.
I hope that helps everyone understand a bit more. We'll work on improving the communication inside our client.
Thanks for everyone!