Adaptability is a very important quality to have. The more you are able to adapt to situations, the better off you will be whether it be in the real life business world, home life, or in a video game.
In WoW, it is important to see when something is not working to make money and adapt to it.
Back in BC, I was a farmer to make my gold. My Paladin was a miner/herbalist with epic flight. I got around fast and made tons of gold (for me in BC anyways). It was enough to buy myself two epic flying mounts and never have to worry about money for repairs/consumables/enchants etc. Back then, I was making 45-70 gold a stack off of Terocone and 25-35 gold a stack from adamantite.
Farming is at an all time high (or low depending on how you look at it). Herb and ore prices have crashed through the floor. Farming is no longer the money maker that it once was, even at the beggining of WotLK. Saronite Ore is going for 15 gold a stack. Icethorn is selling for 15 gold, Lichbloom for 18, Adder's Tongue for 12, and the low 70s ones are selling for 10 gold or less a stack. At this point, it is probably more profitable for farmers to do dailies.....but they arent.
This leads me to inscription. I power leveled inscription and JC on my Druid since he had zero professions. These (especially inscription), have made it so that I did not have to farm at all. Of these two, JC is really more random. When prospecting, you have to hope that you get at least 1 blue quality gem from a stack of saronite, and that it is not a forrest emerald. The JC daily is a nice way to make money, especially if you buy a Dragon's Eye with the mark you get. They sell between 75-100 gold on the AH depending on the day.
Farming wasnt making me as much money as it once did, so I adapated. Now inscription is making me around 1k or more per day. I just buy the herbs off of the AH, use the ink of the sea to make glyphs (and purchase inks for other glyphs), and sell a bunch of the Snowfall ink on the AH.
While purchasing Icethorn, I met someone who had not yet adapted. I was buying stacks of Icethorn when I get a tell asking if I wanted more at a price lower than the AH. Of course I do, I told him. The herb farmer flew from SW to IF where I was, and sold me another 5 stacks at 12 gold a stack. He told me that he is trying to make money for his epic flight form. The thing that really blew me away is that he seemed to be so happy to make that 60 gold.
Thanks to me adapting to my market, the farmers are feeding my gold faster than I can make it. That 60 gold worth of herbs got me 31 Ink of the Sea and 6 snowfall ink.
Those 31 ink of the sea were turned into 31 glyphs which sell for an average of 15 gold. 31x15 = 465 gold. Those Snowfall Inks sell for about 20 gold per. 20x6=120 gold. Even if I did not sell a single glyph, I more than doubled what I spent by selling the Snowfall Ink alone. He spent a decent amount of time to farm all of those herbs. I bought them and less than an hour later, I have a tremendous amount of profit potential sitting on the AH.
The better you adapt to the market in WoW, the more money you will make. I was previously making about 200 gold a day on inscription without even really trying. I decided to make a much wider range of glyphs and be more aggressive, which has netted me substantially more gold. Now I can see how Gevlon made so much easy money. Like taking money from a baby.