Making money in WoW is no different than in real life; find a need and fill it. The more people with the same need, the more the price of the item required to fill that need will be. Simple Adam Smith economics. For example:

Bags. Just about everybody needs bags. The Enchanted Netherweave Bags are especially sought. Tailors make them, and unless you’re already filled with 18-sloters, (like BRK is, thanks to his inside connections with the DCoE Bag Emporium,) you want them. On Madoran, these bad-boys easily sell for 40 gold a pop in the Auction House. Why so high? Because there are enough people willing to pay that price; they have a need, so the DCoE fills it.

The DCoE and I were questing in Shadowmoon Valley this weekend when the pattern for a 28-slot shard bag dropped, (no, I didn’t roll on it, sheesh). Pretty cool, loads of money to be made with that, right?

Nope. Of course, shard bags are only used by warlocks, one of the least-played classes in the game. The market for these is not great, so while the price for a single one may be higher, the potential for profit due to multiple sales is lower.

As a Farmer, it is your first order of business to find out what to farm.

1. Find Out What They Need.

This can be raw materials or finished products. If you don’t aleady know what special items crafters need, talk to your guild’s crafters and ask. They will usually come back with, “If you get any _______ I’ll buy all you bring me.” Let’s continue to use Bags as our example.

Imbued Netherweave Bags take a lot of mats:

72x Netherweave Cloth
8x Arcane Dusts
2x Netherweb Spider Silks
1x Greater Planar Essence

If you’re in Outland, you already know that Netherweave Cloth is dropped by everything. I send a stack of 20 to the guild tailor for every stack I sell on the Auction House. If the price for the stuff is below 4g per stack, then I either bank my stack or also send it to the guild tailor.

Arcane Dust and Greater Planar Essence. Enchanter stuff. I don’t have any, I can’t get any. When I send my trash BoEs to the guild enchanter, I do so because I want her to have the mats to level her profession.

Netherweb Spider Silks. Now we’re talking. Terokkar Forest is stocked with spiders that drop this stuff. However, the drop rate is around 15%, making farming them just boring enough for crafters to not want to do it, and since they only need two of them per bag, they usually buy the mats of the Auction House and consider it the cost of their profession. And tailors have no problem buying these for 6 gold each on my server.

Bingo. That’s our “need” for which we’ve been looking.

2. Get The Stuff They Want.

We want Netherweb Spider Silk. Where do you find it? Terokkar Forrest. There are some specific places there where the only mobs are spiders; no humanoids, no undead, nothing to aggro by accident while you slaughter spiders for thirty minutes. That’s right, I will do a thirty-minute spider farming session and come away with 5-10 silks. That translates to a 30-60 gold profit if I get the going rate for them.

3. Sell The Stuff.

And by that, I mean sell the stuff and don’t let it sit in your bank. Items in the bank do not generate revenue. Sell sell sell. Get rid of it. You’ll never take a loss as you didn’t pay for the stuff you farmed anyway. But letting it sit in the hopes of a higher purchase price is a waste of time and cuts into your cash flow. You want rapid turnover, not inventory management.

The Auction House is the typical vehicle for selling mats, obviously. Since we know tailors need two silks per bag, we list them in stacks of two, and price them so that they are cheaper than the other two-stacks, and also cheaper than those being sold one at a time.

Remember, an item that sells for below auction house average is more profit for you than an item that doesn’t sell at all.

But we can also use the Trade channel. When you see something in the Auction House, you see it with a bunch of items just like it; the rarity-factor isn’t there. When you advertise in the Trade channel, you usually have no competition. Continue to undercut the Auction House price, but not by too much. What you loose in “bargin-buy” status you make up for with “instant-gratification” for yourself and your buyer.

When I advertise a twenty-stack of ore and get a reply, I confirm the order and ask if he wants it send COD, to which they usually reply, “sure”. When you send the order, say thank you and then hit them with,

“You know, I have four more stacks of adamantite ore in the bank. You just bought one stack for 25g, I’ll sell you the other four stacks for 20g each if you buy them all now.”

Now we’ve got impulse-buying, rarity, and bargin-shopping all tied up in one little package. They don’t back away from this deal, ever.

Did you lose 5g per stack if you had sold them in the Auction House? No! Something is only as valuable as someone is willing to pay for it. If nobody is willing to pay 25g per stack of adamantite, it’s not worth 25g. So instead of 100 adamantite ores in your bank collecting dust, you have 105 gold in your pocket.

And as I said, this does work. Look though my blog, track my gold. BRK is closing in on his epic gryphon, are you?
Edit: Subtract 10 gold from that total. I completely forgot that I owe the DCoE for an Arcane Tome I sold for her. If she reads this, I could be in big shadow-priest trouble. Keep it under your hat, please!