Bitcoin mining hardware investment
Best Bitcoin Mining Hardware (December 2017) | Anything Crypto
crypto currency - MGT Capital Investments
Jun 13, 2017 7 reasons Bitcoin mining is (likely) not worth your time in 2017. and even; Petahash = PH/s (quadrillions of H/s). In early 2017, Bitcoin's collective hashrate reached nearly 4 Exahash. This represents a tremendous investment into mining hardware, the R&D of such hardware, and electrical expenditure.
BitClub Network Review - Bitcoin Cloud Mining Pool Business