I have 3x a invite a friend code from gamescon 2012, since my friends are playing and the codes
expire on 31 january 2013 its more usefull to give them away to someone that that can use them.
you can only use the invite code while creating a world of tanks account and the code is only valid
for european servers. while creating a account you can enter this invitation code.
The code gives 3 days premium + 1000 gold.
Let me know if your interested in one of the codes, i got 3 and the first to respond will get them.