Bitcoin - a system of electronic money is attractive because it does not control and is fully autonomous. Speed computing hashes in its p2p-network exceeded 1 eksaflops, ie it was productive TOP500 list of supercomputers together at 8.
Bitcoin feature is the ability to use video in your own PC for "production" of virtual money. The more computers involved in the calculations, the higher the total capacity of the entire network and harder to make money.