The economy of EVE Online is a strange one -- possibly unique, in that the value of the game's currency (ISK) has a verifiable, equivalent real-world value. This is due to the fact that CCP allows players to buy gametime codes outside the game (perfectly normal), and then use those codes to create in-game items: PLEX, or Pilot License EXtensions, which can be used by the original player or sold on the in-game market for ISK (something not seen in any other game of which we are aware).
This setup creates a couple of interesting effects. For instance, a player with a sufficiently profitable character can basically turn EVE into a free-to-play game, simply buying PLEX off the in-game market with their character's wealth, rather than paying a subscription fee. It also allows people to report fairly accurately on the real-world monetary equivalent of the damages incurred by the latest hulkaggedon.
Most importantly, with the help of CCP, it provides EVE players with a unique opportunity to help those in need in disaster-stricken areas of the world by donating their character's wealth to the cause.