I wrote about trial end error last week as an important technique in gold making. As you all know understanding how other people play the game is crucial to help you find good goldmaking methods. If you know what people are trying to do you can find profitable ways of helping them.
Know your clients
If you know why people want an item you can sell it more easily. This is the idea behind concepts like neat stacking for instance. Trying a lot of gold making methods will give you amazing insights into how the supply chain for various markets look. This will then help you make decisions in cases of potential market resets or other changes.
It all fits together
Gold making activities are all connected in various ways. A change to cloth yields can have large effects on secondary markets. Suddenly the leatherworking shuffle is cheaper than the cloth shuffle, the price on enchanting materials increases as well.
What you learn
The main things you learn by trying various methods are:
Which materials are used in which crafts and crafting processes. Knowing how much an where a material is needed is great if you are trying to flip or farm it, as you can target your customers directly with your operation.
You also learn how fast materials can be attained if you try some farming. This is great in situations where the AH is overflowing with materials or if it is running dry. You can more easily evaluate how quickly people can refill and make a judgement on whether or not a price change is temporary or likely to stick.
Seeing how it all fits together
The sum total of the world of warcraft economy is of course too much to keep in your head. Even so the larger the portion of it that you hace dabbled in and understand the easier it gets to find new markets as well as to make necessary changes in the markets you are active in.