There was an interesting question posed to WoW Insider today under The Queue, their frequent Q&A post about all things WoW. The question was regarding which daily quests to complete in order to make the most gold. WoW Insider correctly assessed that the key to profitable daily questing is finding the right mix of time invested vs. reward. Spending too much time doing dailies when you could be doing more profitable activities is, ultimately, not profitable. They go on to recommend completing The Oracles daily quests for profit as they take a minimal amount of time invested. WoW Insider also points out that this can change server to server depending on population within the questing areas and because of this many people have reported great financial success with the Sons of Hodir daily quests.
Of the people I’ve spoken with, it is generally agreed that completing daily quests is not the best way to get rich in the game. There are far more profitable ways to make money simply by manipulating the AH or farming items. Even some crafting and other professions can make more money if managed correctly. That said, if the quest offers a needed reward such as reputation or tokens of some kind then the time investment is worth it. Another thing to consider in terms of professions is the abundance and type of resources in the area. Along these lines I would suggest that if you want to make money completing daily quests do so in an area that rewards reputation or tokens or both and is located in an area with farmable resources. By way of example consider the following:
Miners/Herbalists: Sons of Hodir daily quests as these both reward reputation and provide access to the highest level ore and herb nodes in the game. Daily quests in Icecrown are good for miners and herbalists for the same reason although many of the quests don’t offer any faction reputation. The Sholazar quests mentioned above also can be quite profitable as there is an abundance of both ore and herbs to be found within the questing area. This area is particularly good if an herbalist is farming lower level herbs such as Goldclover and Adder’s Tongue.
Enchanters and anyone without a gathering skill: Wintergrasp daily PvP quests. This is a great area to kill-farm in general as the elementals within the different areas drop crystallized components to make eternals. Note that completing the dailies in this area will require some successful PvPing on your part and that the farmable elemental mobs disappear while the battle for control of Wintergrasp ensues.
Daily quests are certainly one of many ways to make money in the game. Do a little research and find the area that works best for you in terms of profession, desired rewards, and time involved.