I've got to say, I'd be really interested in knowing what kind of math people are using to try and make the mining thing work.

Looking at the prices of the 1 and 2 TH units that are coming out - and running that thru one of the mining calculators - I'm really at a loss to see where anybody is ever going to make the money back on those units.

Even looking at another example:  the cost of an S1 right now - which is ~ $446.50  ( ~$500 per BTC X .893BTC on Bitmain) - and then plug that into one of the calculators - and what I get at the current difficulty level - is 54 days to pay the machine off.

If I plug in the estimated next difficulty level of 6,085,479,004 - that goes up to 69 days, and even that is not bringing into account subsequent difficulty level increases.

Just throw in 8,085,479,004 (because I don't feel like trying to calculate where the higher difficulty levels will actually come out) - and you're talking 100 days to pay the machine off.

I gotta say I'm beginning to see the viewpoint of all the people who are saying that the mining thing is just a losing game.  The numbers simply don't work.

Granted - all the above numbers are based on the current BTC price.

But even if I bump the BTC price up to $700 - that last calc of 100 days only goes back down to 65 days (all other factors being equal)