Recruit a friend activity is very popular in world of warcraft, but many people do not make full use of this awesome activity, so, i think it is necessary to write a small guide to let people know how they can get free 30 days of a RAF linked account with TBC on it.
As you know, Blizzard sent a few people a key for a free month of WoW to give to their friends. That code can be used to upgrade a trial account to a "Battle Chest" account, which is just a normal account with TBC as the max expansion. So here's what you do:
1) First, choose who you want to level the characters, as any characters on the free account are pretty much gone after the 30 days unless you xfer it to your main account.
2) Then, have the person A who wants to level his main account recruit-a-friend to person B
3) Person B should then start the trial then "upgrade" and put in the free 30 day code that one of them got
The accounts are then linked, person A gets a free month, they both get the amazing exp boost (I've helped my friend level two chars to 70 in 3 days so far, just grinding dungeons with one of us as a tank). Now this only works until level 70 because obviously you can't level past what the expansion cap is on your account. But besides that you have every other perk of RAF, summon friend, grant levels, etc. Enjoy!