Ah that explains what I perceived was a very over-engineered way of measuring the current. I've used several of the clip on readers myself in the UK - trivial install - and in fact several British electric providers have sent out their own current usage displays to customers.

Then again I haven't seen any popular usage of NLM (several apps were trying when I last looked) that can determine how much an individual appliance is costing really simply, i.e. the hairdryer cost $3.12 to run this month. That info could be really compelling and could spin out more ideas but doing this non-intrusive load monitoring sounds rather difficult with your data collection method.