Hmmm. Regarding the "relative profit" of small scale mining: There must be some gain in efficiency to moving to these largescale mining systems. Or everyone would just make lots of the small scale systems, right?
Obviously, someone with 10,000 watts of USB thumbdrive-sized miners would run into the same costs eating his profitability: 10,000 watt of electricity bill, 10,000 watt that need to be cooled, etc.
At least with larger setups, you get to pool your costs, and your power usage would be more efficient.
Now, the counter to this are the micro-mining setups where you are using very little electricity, such as using a flashed router or Raspberry Pi to host your USB miners. In this case, you could even probably run it off of solar in most places to make running costs actually zero. You'd have maybe $100 more in initial costs (for solar), but you'd have no ongoing costs, only profit.
BTW, your username is funny to me - those are my initials. It's like I'm having an argument with myself. It's been known to happen.
I meant a Raspberry Pi running as the host for a bunch of USB ASICs. This way you are effectively reducing the power requirements of the host to the minimum amount. You could do the same thing with any low-power embedded system that could run bfgminer or cgminer and keep up with the network.
This would be opposed to running a Linux or Windows desktop system as a host.
People actually went as far as to sneak into Butterfly Labs' facilities and found no evidence of it.
Do you want to be the punter or the house?