From Melanie Swan at http://www.melanieswan.com/social_finance.html
"There are two aspects of virtual world economies:
- Intra-world trade – barter or in-world currency based goods and services transactions. Example currencies: Linden Dollars (Second Life), Simoleans (Sims Online), Gold (Ultima Online, World of Warcraft)
- RMT (real money trade) - the exchange of virtual world goods or currency for physical world currency. RMT is conducted informally and through currency exchanges, on eBay (thousands of concurrent auctions) and through other dedicated sites, which often have superior exchange rates."
"MMORPG (massively multiplayer online role-playing game) video game (Ultima Online, EverQuest, World of Warcraft, Lineage, etc.) and metaverse world (Second Life, Sims Online, There) economies are rapidly eclipsing the GDP of many countries in the size and volume of their economic activity. For example, metaverse world Second Life has been recording $7M USD of transactions occurring in-world per month since July 2006, and surpassed one million registered residents on October 18, 2006. Economist Ed Castronova was one of the first to formally measure MMORPG economies and estimated that in 2004, the economic activity in and around EverQuest was comparable to the economy of Namibia." (http://www.melanieswan.com/social_finance.html)