Players that have learned the enchanting profession can disenchant (break-down) certain items into essences, shards, and dusts. These materials are primarily used to give added enchantments to items, and to raise one's skill in enchanting. For more information, see disenchanting.
Many players attempting to raise their enchanting skill do not wish to kill monsters for items to disenchant. They would rather buy them in the Auction House for quick skillups. Other players need the materials to give to an enchanter for the purpose of gaining enchantments to their own items.
Disenchanting for profit involves buying, looting, or creating an item in order to sell the materials, usually on the auction house. This can often lead to a greater profit than selling the item as-is.
One popular example is Tailoring: players who have learned both tailoring and enchanting can buy or loot the materials required to create quality cloth items, gaining skillups in their tailoring skill. Normally these items would be difficult to sell in bulk, and rarely yield a profit. However, the items can then be disenchanted, and the materials received are much easier to sell.
Another example, in the form of an add-on, is Enchantrix. Enchantrix works with Auctioneer to determine a suggested price range for the potential mats received from disenchanting armor and weapons being sold on the Auction House. If the item is being sold for less than the average value of the disenchanted materials, it is suggested that you buy the item, usually by Auctioneer's [Bottom Scanner]]. For more information, see the Auctioneer or Enchantrix websites.