One of the first things to start learning about when becoming a successful gold making goblin in World of Warcraft is the Value of an item. 

• How do you place value on an item? 
• How do you know what can be sold for a nice profit? 
• How do you know what will sell and what will not sell on the Auction House? 
• How much should you sell it for?

Learning to place value on items within the game is a very complex lesson, but one of the major contributors to the value (or worth) of an item is the Demand for that item.

• Is the item needed by certain Professions?
• Is the item rare and hard to collect?
• Is the item required for a quest?
• Is the item used for leveling characters?
• Is the item required in a crafting recipe?

There are many factors that will contribute to the demand for that item.  Without any demand, an item surely will not sell.  Let’s look at a specific example of an item that has a demand and will sell on the Auction House in World of Warcraft.

Low Level Tanking Shields and Random Dungeons

Level 15 is the earliest that a new character can start to use the Random Dungeon Finder tool.  This in game tool allows characters to join for dungeon groups without having to form a party first.  This was an excellent addition to the game that allows for quicker running of dungeons, especially at the lower levels.  To be even faster at getting queued, many players will have their character sign up as the tank role for the group.  These low level warriors and paladins will head to the auction house to buy a shield to start off their dungeon tanking career.  For this reason, you can sell many of the level 14, 15, 16 green shields that you find off of mobs while leveling and questing in Azeroth.  If they have stamina and strength bonuses they can sell very well.  These green tanking shields will sell for far more on the auction house than they will to the vendors.  Even healing stat shields can sell to Shaman and Paladin Healears that are joining up in the Healer role for the Random Dungeon Finder. 

So make sure not to trash or vendor any of the level 14-16 green shields.  Post them on the auction house.