But that's actually less efficient! You are making negligible amounts for each small USB miner, and whoever you are giving them to is probably spending more in the electricity than you are making! It would be just as profitable to ask those million people to just give you a penny every day or two.
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.
There is some scale level where you've captured all the manufacturing efficiencies (e.g. the asicminer boards in those pictures are only 10GH/s per board), and once you've crossed that it's generally more efficient to distribute the hardware because you can make better use of low level waste heat as home heating (or at least not having to actively cool it).
I doubt the bitcoins mined via raspberry pi would ever cover the sunk cost of $100. When it comes to mining bitcoins ASICs are a millions times more power-efficient than the raspberry pi.
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.
