Well-Defined Currency. Almost all previously de- ployed computational markets have used a virtual cur- rencies instead of real cash. The low barrier to utiliza- tion and low stakes in case of deployment error make simple closed virtual currencies attractive to developers. In these scenarios, it is all too easy to skip the monetary policy considerations that make currencies work. For all of their bootstrapping advantages, virtual cur- rencies require initial thought and ongoing care to func- tion properly. Virtual currencies often suffer from a lack of liquidity, making it difficult to convert into or out of the virtual currency. As a result, these ersatz currencies are quite limited; certain usersmight be willing.
