What is the correlation between real and virtual money?

Users pay real money to purchase virtual goods, such as points, weapons, virtual currency in virtual games. And in some situations like online shops, it is possible to exchange virtual money into real currency or goods. Since there is real value of virtual assets and money, an emerging virtual black-market in which virtual weapon and currency is sold and bought is growing.

In the case of Second Life, it has its own economy and a currency referred to as Linden Dollars (L$). Residents create new goods and services, and buy and sell them in the Second Life virtual world. There are also currency exchanges where Residents can exchange US$ or other real world currencies for L$. Millions of Linden Dollars change hands every month for the goods and services Residents create and provide.