To fill his evenings, Castronova did what he'd always done: he played video games. In April, 2001, he paid a $10 monthly fee to a multiplayer on-line game called EverQuest. More than 450,000 players worldwide log into EverQuest's "virtual world." They each pick a medieval character to play, such as a warrior or a blacksmith or a "healer," then band together in errant quests to slay magical beasts; their avatars appear as tiny, inch-tall characters striding across a Tolkienesque land. Soon, Castronova was playing EverQuest several hours a night.
Then he noticed something curious: EverQuest had its own economy, a bustling trade in virtual goods. Players generate goods as they play, often by killing creatures for their treasure and trading it. The longer they play, the more powerful they get  but everyone starts the game at Level 1, barely strong enough to kill rats or bunnies and harvest their fur. Castronova would sell his fur to other characters who'd pay him with "platinum pieces," the artificial currency inside the game. It was a tough slog, so he was always stunned by the opulence of the richest players. EverQuest had been launched in 1999, and some veteran players now owned entire castles filled with treasures from their quests.
Things got even more interesting when Castronova learned about the "player auctions." EverQuest players would sometimes tire of the game, and decide to sell off their characters orvirtual possessions at an on-line auction site such as eBay. When Castronova checked the auction sites, he saw that a Belt of the Great Turtle or a Robe of Primordial Waters might fetch forty dollars; powerful characters would go for several hundred or more. And sometimes people would sell off 500,000-fold bags of platinum pieces for as much as $1,000.
As Castronova stared at the auction listings, he recognized with a shock what he was looking at. It was a form of currency trading. Each item had a value in virtual "platinum pieces"; when it was sold on eBay, someone was paying cold hard American cash for it. That meant the platinum piece was worth something in real currency. EverQuest's economy actually had real-world value.
