Product review (1 stars): This scam explained mathematically
I'm a registered Professional Engineer and thought I would try to explain this scam mathematically, since I have not seen it done elsewhere here yet. Assuming this works as advertised, it will still not save any money on your electric bill. Why? Because electric meters measure and bill you on watts consumed over time (watt-hours), not on volt-amp hours. If you watch the infomercial on this device, what they do is turn on all these loads, and show you as the usage creeps up to about 5 amps or so. Then they plug this thing in, and the value drops down to about 3 amps. So it makes you think that the device is actually saving you 2 amps. But it's not -- because you're only being charged for the real power component in the first place, which in this case is 3 amps, not 5. Here's how it proves out mathematically:

110 volts x 5 amps = 550 volt-amps
power factor = 0.6 (the more inductive loads you have, the lower this is from 1.0, which is unity)
550 volt-amps x 0.6 pf = 330 watts
330 watts / 110 volts = 3 amps <-- what the electric company actually bills you for

I'm not sure how clear this comes across, but the bottom line is that electric meters only charge you for watts. So if you have loads that sum up to a low power factor in your home, the amps you read on your electric panel are not what you're being charged for. What this device does, assuming it works as advertised, is act as a mini Power Factor Correction (PFC) unit, by using capacitors to cancel out the inductive imaginary power portion (vars) and give you a unity power factor (1.0).

In large-scale industrial plants with big motors, power companies will typically charge a penalty if the loads they are consuming cause a facility power factor of less than 0.85-0.9. And in that scenario, installing large PFCs to eliminate this penalty may make sense. But residential consumers are not charged penalties for low power factor, and unless that happens, this device will not achieve what it claims to do.