Making gold without even knowing it.

Many players aren't gung-ho about gold making and would rather do things that they actually enjoy in the game. I don't always feel like making gold, but in this game it's often something you cannot help but do. Whether you like it or not, you can be making gold while completely unaware. In essence, you can be doing something completely different, with another goal in mind, and still be making a ton of gold in the process. Reputation grinding is one of the many ways that players can do this and you will be surprised at the amount of gold that you can bring in while grinding reputation.

The Burning Crusader, for example, is an achievement that will require you to raise five Outland instance reputations to Exalted. Most of these reputations will require you to do a great deal of Outland instance farming where you will pick up items that still sell for extremely competetive prices on the Auction House.

A few of these items include:

Netherweave Cloth
Outland Greens
Outland Blues

If you have a profession such as Herbalism or Mining, you can also gather all the Ancient Lichen, Felweed, and various Mining Veins you see throughout the instances to net even more gold in the end with negligible losses in time spent grinding. If you add all of the grey items, weapons, feathers, armor, and other junk you vendor, you are left with a formidible gold making method that will net amazing gold per hour without you even knowing it!

::Xalted