Hello there.
I found an exploit today which can be done with Character transfers.
I'm not sure if it is known already, so forgive me if it is old.
1. It doesn't move the character forever, it is free however.
2. It will make the character "locked" on it's old realm after a day or so, making it unable to play with.
So what good is it?
Well for example, you have a lot of gold or items on a very populated server and have another character which you play on a less populated server.
So what you could do is make a level 10 alt or so, give him tons of gold/items, move them over to the realm where you're main is and just send them the items, after a day or so the character will be transferred back to his old realm and make him "locked".
So how do you do this?
What you need to be able to is pay through paypal.
Just create a paypal account, link it to your world of warcraft account, and follow the paypal payments when you transfer the character of your choosing.
When done, because Blizzard doesn't check if payment is received, after about 30 minutes the character will be on the server where you desire it to be.
Personally I just did it to move some items to my new main which is on a less populated server, without having to pay 20 euro, which is expensive imo..
I'm sure there could be other reason, but I leave that to you to find out.