Blizzard
Use the Recruit A Friend button on the in-game Friends List to send a customized email invitation to your friends. Once they accept and create an account, you will be linked with your recruit so that you can find them in-game.
New
If your friend pays for two months of game time, you'll get a month of game time FREE!
If your friend pays for three months of game time, you'll receive a choice of EPIC in-game mounts or special pets.
Old
If your friend purchases a full copy of World of Warcraft and pays for a month of subscription time, you'll get 30 days of game time FREE!
if your friend pays for two full months of game time, you'll receive a choice of EPIC in-game mounts or special pets.