Will I be able to play the game with CD key only?

I played private servers for years, and now decided to try retail because I'm starting to work soon, and there will be some serious cash influx :) I installed trial, and 6 hours later decided I can't wait for my first salary - I have to upgrade to regular wow right now :D

My problem is in the following: I have exactly 20 euro in my pocket, which allows me to buy only WoW vanilla. Further, since I'm not working, I don't have a visa, and I certainly can't ask my parents for credit card to play WoW :) I heard that if I buy vanilla, I will get a free month of play, which is just what I need. But I also heard that I can't activate that month without credit card and/or game card.

I sent an email to Blizzard with this inquiry, but they're not replying still (2 days).. Can anybody tell me if I can claim my free month if I have only CD key?

Thanks in advance, I'd really appreciate an answer|||You need to pay first to get your free month...either by credit card or game card.|||Well, I would level up your character first whilst its FREE and then pay when you get to Level 20 ( Top level for Trial ) This will mean less time leveling and more time doing Dungeons Etc.