Ah crap, I just realised that I have to change mah address at WantItAll still .......... (if I can remember the password that is)
oh crap! I forgot to sign up at Wantitall!
Do we just have to sign up? Will MyGaming automatically know who we are?
I think the way it is supposed to work is you give TM your name and surname and size of the teeshirt, like he said in the OP.
Based on that (your Name and Surname, since people should be using their real names) WantItAll will know who to send it to.
(Yes, it does leave room for some errors with common names, i.e. if you are Koos van der Merwe or something, but that can be sorted out by supplying your e-mail address on the site as well)
How would we know if they associate the correct want it all account with the correct My gaming account?