Earthing is an alternative medicine therapy where individuals "connect" with the Earth's negative surface charge. Apparently this is supposed to help you "balance" your internal circuitry and restore a lost electrical charge. On the Earthing Institute's website they claim Earthing can help improve blood flow, reduce inflammation, reduce pain, and allow for deeper sleep.
 How to do it
To establish a connection to the ground it is suggested one can simply walk around barefoot. Unfortunately if you're a
crank conman you'll find it hard to charge people for walking outdoors. So the solution is to charge people for special mats they can plug in to their walls and rest their feet on. Presumably the electrical design is fairly simple, just involving a dummy plug with a connection to the mains safety ground.
Of course it's not a bad idea to try and get outside on a regular basis, but it's unlikely that walking barefoot would be better than walking in shoes, particularly in cold weather or other conditions where exposed skin could be dangerous. In particular, walking barefoot outdoors can sometimes lead to parasites (plantar warts or hookworm). The mats, on the other hand, could have no conceivable benefit beyond the placebo effect. Of course an advocate of Earthing will tell you a different story, about how supposedly because the nervous system uses electric signals to communicate literally grounding oneself electronically will help your nervous system function.