ok, so lets be pedantic
.
Am I correct assuming that we agree that bitcoinmaker is not just a scam, but specifically a ponzi type scam (either that, or a vehicle for Ingvar Kamprad to spread his wealth around).
If so, would it change anything if they were actually mining with 1 antminer ?
If not, what about 10? 100?
If not, then how is it different from the situation where amhash would be selling a fixed mining profit of x% per year ?
BTW, if you disable sigs, are you able to have one yourself?
Whether or not they are mining has no real impact on whether or not it is a ponzi. Boyko obviously had some mining power at one point (rented or not, who knows) and that is a ponzi.
The hallmark of a ponzi is that the returns are not based on actual revenue, and are paid with investor money. I'm not sure exactly where you'd draw the line on a fractional reserve mining operation; as much as I hate to say it, it probably boils down to intent. A proper company would limit the offering to actually available hardware (covered by your unlimited IPO point), but if someone like Bitmain, KnC or Bitfury didn't do that and had a huge sales rush that put them past their actual capacity it wouldn't make them a ponzi.
A permanent fraction mining operation is a more complex beast and you'd have to judge them on a case by case basis. There exists the edge case where a real mine could be slightly fractional, but still pay out real revenue because their maintenance fees are much higher than their actual costs. They're still subjecting themselves (and their customers) to exchange rate risk, but I'm not sure I'd fully qualify that as a ponzi.
Also note, I'm not saying that AMHash would offer a fixed mining profit per year and actually pay it out. I'm just saying that they could advertise "guaranteed profit" with no real backing, and if it works out, great. If it doesn't, tough shit for you. Not a ponzi, just scammy false advertising.
On the signature, no idea. I don't have one.