Diablo III's downfall was that there were price floors and price ceilings. They set a minimum price for gold, which would be higher than its true value. This

Diablo III's downfall was that there were price floors and price ceilings. They set a minimum price for gold, which would be higher than its true value. This led to people selling their gold outside of the RMAH, and killed the liquidity of the in-game currency. Items also had a maximum price limit. This meant that items worth more than $250 USD at the time had to be sold for lesser value items, or for gold (which had the downfalls listed above). The problems with Diablo III were the restrictions on the marketplace. Blizzard never allowed prices to hit their true equilibrium, and it created an off-site black market along with other inefficiencies. There is no reason that a game economy should be ruined in one way or another by a real-money exchange rate. There are many games where players buy & sell in-game currency for real money, where the in-game currency holds a very steady real money value. Take Runescape for example. One million Old School Runescape Gold has been worth roughly $1 USD for the past 6 months. The volume of in-game currency which has been bought and sold in that time period is in the tens of millions of USD. Source: I run http://r2pleasent.com http://r2pleasent.com - a site that buys and sells in-game items.