You are correct, a mule is a second, third, etc. character whos main purpose is not to grow or train skills, tho they can, but is to store and or sell items. For 1$/mo on your account you create a new id, a new character and use him to store or sell items. Whereas now you can only have 7 item in the AH, with a mule you could have 14, plus his inventory space and mog house space for storate of crystals, armor, etc. Some people who do a lot of trading or want to be able to look for or check item pricing in different cities will get three mules, one in each starting city, so that you can be in Jeuno, Norg, etc and still do business in any of the starting cities. The way it works.... In each city somewhere near the AH is an NPC character who will transfer items to another character. When you click on him a trade menu pops up, you have to first enter the name of the character you wish to send something to (friend, or mule, or whomever), you must then hit ok, and then can place items in the trade menu. You then hit OK and the items darken, meaning they have been sent. The recieving character has to go to his mog house and open the delivery box and voila, there the items are for his use, sale, etc. Money can be sent as well as items, so it is possible to be in Jeuno, send money to your mule in Sandordia, have him buy an item you want at Sandorian prices, and then the mule can send it back to your main character. All legal and easy, just takes some time logging in and out characters if you do this very much. Good Luck and happy mule train.