Guys I really appreciate the time and effort put out by some of the members to take out so much calculations and facts. Although no one have any personal motive but still this much effort is commendable. I was also researching GBC for long time and took lot of user feedback which turned out to be positive as there is not issues with payouts. I myself also put some calculations in place and somehow their model looks feasible.
Current BTC mined per 10 minutes (average): 12.5 BTC
Current BTC mined per hour (average): 75 BTC
Current BTC mined per day (average): 1800 BTC
Current BTC mined per month (average): 54000 BTC
GBMiners Hashrate: 5% of total available on Blockchain
GBMiners mined bitcoin per month: 2700 BTC
They may have been earning some transaction fees as well.
GBC contract validity: 18 Months
Average life of mining hardware: 4 years (estimated)
Months left after users contract expires: 30 Months
Now see, how is it happening. The hardware purchased by any user will server atleast 18-30 more months and their hashing power is increasing day by day for new users. That is the reason, they go with very rough calculations because they know this can be done this way.
I feel this is that magic which is working for them, I cant say they are scam because of committed payout. They have kept the contract prices same even after prices went nearly 3 times high in a year and with that they can plant more servers or can sell the BTC bulk at peak prices and can buy at lower rates after the crashes.
I feel Amit will not highlight himself so much if he is not genuine because wherever he will stay after any scam, govt. will catch him bcz the amount at stake is very high here. They are saying that they are getting registered in India in March 2017, and if this happens people will not face any issue in my opinion.