Cooking recipes have become a much wanted pipeline for making a lot of gold fast in World of Warcraft, since the release of the Wrath Of The Lich King (WotLK) expansion.
Because of cross-faction trading, cooking recipes have always been a good source of gold on WoW. But ever since achievements came out, a lot of players have been wanting to buy the cooking recipes, and because some of these recipes are hard to find, they tend to go to the auction house to buy it.
The single most valuable currency in the World of Warcraft game is gold. Just one piece of gold is equal to one-hundred pieces of silver and 10,000 pieces of copper.
Earning gold in gameplay is usually done via hunting, questing or crafting. When you hunt and kill, you can acquire whatever your enemy drops and sell it to vendors. When questing you can earn both money and items.
Through crafting you can create items to sell to vendors.
Typically in role playing games a lot of the fun comes from the challenge of having to attain certain levels of currency in order to purchase items or powers that you want.