Runescape developer Jagex claims that it has managed to reduce illegal gold farming in its free-to-play MMORPG by a notable 81 percent in a single month, through the use of a "Bonds" real-money system.
While I originally planned to cover this as part of Issues in Armour Tiers, the Task equipment turned out to be so messed up and too large issue to tackle that I had to give it its own section in this thread.