Good job making me feel like one of Skinner's pigeons! Clicking and clicking for what appears to be diminishing returns. Little pellets of food come out of the chute now and then, so I peck and peck like mad at the lever.
But after 174 coins mined, the rate of return seems to have dropped to approximately zero. Is there a limit to the number of coins? Perhaps an exponential distribution to the frequency of gaining coins by mining?
Not that it matters. I'll click away for the next 17.5 hours, like a good little pigeon.