After looking around G-mail Help I guess I don't get to invite friends...
How do I invite others to join Gmail?
Answer return to Help Center
Gmail gives users the ability to invite friends to sign up for Gmail accounts. If you don't happen to see a blue 'Invite a friend' box in your account, please be patient -- Gmail invitations are always randomly distributed.
For now, we can't give you more invites. Gmail may, however, randomly grant invitations to your account as they become available in the future.