ige (Internet Gaming Entertainment) is an intriguing website/company that allows people to buy and sell gold for MMORPG. So people who don't have time to farm can busy gold and use it for them or their guild. What is interesting is that people who used to do it on eBay now have a specific platform for that. The market must be huge. Now, if you look a bit at the creativity about this phenomenon in terms of tools/websites/information available concerning gold/goods, this is quite crazy (price comparators...):

Eye on MOGs: "Eye On MOGS is a MOGS search-engine cum comparison/availability tool. Our aim here has always been simple – to provide you, the user, with a quick and easy way to find the virtual good you want; when you want it and for the best price for you"
Gold Pricer: "This website is dedicated to finding you the lowest priced World of Warcraft Gold for your server on the internet. Every day, we search more than 30 different providers of WoW gold, to ensure the prices we display for your server are completely up to date".