RAF Question

[pghmyn]

I have been browsing around the site and see these awesome deals for trades of buying game time for $8-$10 a month by using RAF.

How does this exactly work? I've done RAF when it first started a LONG time ago. Would I be able to have game time added onto my existing account?

[Fadelol]

How can I earn the free 30-day credit?
For each friend or family member you refer who upgrades to a retail version of World of Warcraft and purchases 30 days of game time via subscription or game card, you will receive a credit for 30 days of free game play.

Blizzard Support