Many people credit daily quests with making earning gold in WoW easier, and that part of the reason Blizzard added so many of them was to combat gold farmers by making lots of gold available to everyone. I’m not sure if anyone has really broken this down before, but I believe daily quests actually make earning gold harder for most players.
Before TBC and daily quests, there were a few tried and true methods to really ‘grind’ gold. You either did gathering circles in certain zones, or you farmed particular mobs that dropped items of high value, usually something related to crafting. Pre-BC, crafting was the main ingredient that kept the economy in WoW moving, as supply/demand was highest in that area. Epic gear and other non-crafting item prices remained relatively steady, as the supply/demand of those items did not change.
Another pre-BC factor overlooked is the amount of people who actually went out and farmed gold, and the frequency of that farming. Raiders did it to pay for repair costs, which were somewhat high before the nerf, and also for consumables. Crafters would farm to support maxing out a skill, or to craft the one or two useful items they needed to make. Everyone else would farm whenever they needed money for new enchants, or perhaps some upgrade in the form of a BoE epic. An epic riding mount, while not easy to get, was not priced as high as the current 5k cost for an epic flying mount. And since we are talking pre-BC, you did not have the added cost of gems for gear.
The real problem with daily quests is that the hardcore players are able to grind them out at a must faster rate than the casual player, and a casual must dedicate greater amounts of time to the gold grind in order to keep up. This all reflects on AH prices, as anything of real value is priced ridiculously high. Now instead of taking 1-2 days from your normal activities to grind out some gold, a casual play has to dedicate far more time in order to achieve the same result pre-BC.
Dailies also encourage gold grinding from the entire player base, popping up each day with the lure of the blue !, and if everyone is grinding, it just raised the price bar that much higher. While before grinding gold was something you MIGHT do, grinding dailies is something everyone does when they hit 70.
My theory is that dailies and the massive inflation on prices might actually be a positive boost to the RMT industry. If I’m a casual player with disposable income, why spend time grinding dailies for days when instead I can buy gold, especially now that gold is MUCH cheaper thanks to all the methods Blizzard added. Sure that 5k epic flyer might seem expensive at first, but if we are comparing that price to all the top tier enchants and gems needed by hardcore players, a casual actually gets a bargain if they go the RMT route now than they would have pre-BC.
Of course dailies serve as yet another time sink for Blizzard to keep its players interested, but is a daily grind for inflated items really a step forward in end-game design? Is it really better to repeat the same set of ‘quests’ each day instead of going into an instance with 4 others, or a raid with 10-25? Has the end-game in WoW actually improved with the addition of daily quests?