I was emailed this on launch day and im a lil confused.
I bought the game online from SE and my Collectors Edition is already registered to my service account.

So my question is, what do i actually do with the code?
Do i add a new service account or what? I tried entering it as a bonus code but that wouldn't fly.

"Thank you for purchasing FINAL FANTASY XIV: A Realm Reborn.
Here is your Game Activation Code
XXXX XXXX XXXX XXXX XXXX
How do I redeem my Game Activation Code?
You can redeem your Game Activation Code when prompted the first time you log in to the game.

Alternatively you can redeem your Game Activation Code via the Mog Station here."