Get them here:
http://eu.alienwarearena.com/giveaways/the-world-of-tanks-bonus-code-key-giveaway
They give 1 day of Premium and one case of Cola. You can also get new ones even if you participated in the previous giveaways.
Invite codes:
http://eu.alienwarearena.com/giveaways/the-world-of-tanks-invite-code-key-giveaway-for-new-players
