Retainer part of many things

  Having your mule in Final Fantasy XI is all but required if you want to play the game seriously, and absolutely required for crafting. Finding a way to sell all of your crafted goods is often a burden, especially since the game has sharply divided goods that are profitable and those which make you lose enormous amounts of cash. Between storage space and setting up a bazaar, there's always been a sense that the development team wanted to make crafting a viable method to playing the game but never quite hit the right formula.
  Final Fantasy XIV's devotion to the art clearly goes beyond simply allowing you to craft and level in the same motion. The fact that sell Final Fantasy XI Gil you will, in effect, have a mule that automatically does the selling for you whilst offline is somewhere between an update to the status quo and a deranged version of The Sims 3, but in a good way. (All of you who immediately piped up with "actually, that's more like The Sims 2: Open for Business" are excused. You get a gold star for the day.) It also helps serve to push the game's economy in a player-driven direction.