Because of places like this. It's far beyond a home computer and a couple of extra hard drive. Remember, the people mining gold in Cali didn't get rich, the people selling the shovels did.
http://kotaku.com/inside-a-bitcoin-...medium=recirculation&utm_campaign=wednesdayAM
"The monthly electric bill is somewhere around US$60,000!"
http://kotaku.com/inside-a-bitcoin-...medium=recirculation&utm_campaign=wednesdayAM
"The monthly electric bill is somewhere around US$60,000!"