Bitcoin (unit of BTC) is now most successful and controversial virtual money which is issued in 2009 by a pseudonymous developer named Satoshi Nakamoto. As of March 2013, Bitcoin with a valued of 300 million US dollars is in circulation. [L5]
Bitcoins are issued under certain rules and has a declining issuance rate which will be reduced to 0 by 2040. And by that time, the total amount of Bitcoins will reach 21,000,000 BTC(10,500,000BTC at the very beginning). As there is not a central management regulation, security of the system is ensured by its special rule which stated that the new “gold” will be issued to those (miners) who help calculate and validate the effectiveness of transactions. The calculation consumed certain the resource of CPU as well as a huge amount of electricity which can be seen as the value bases for the currency. In order to make the money enough for trade, Bitcoin is divisible to eight decimal places.
Like Wal-Mart purchased Card, we now have Bitbills(http://bitbills.com) which is a kind of prepaid card storing Bitcoins to transact in real life stores without internet connection. Users can either exchange the cards at face value (for instance at a retailer) or redeem the funds and spend them in the Bitcoin network.[L2] According to the creator of this innovation, since their launch on 9 May 2011, the demand for Bitbills has been substantial. [L2]