Those new type of switches hit the market over 6 months ago. They use the energy of the persons "button pushing effort" to generate a short pulse of electricity. So, it's good for impulse event type operations, like energizing a transmitter for a VERY short period of time to send a VERY short message. The original intent was for short-range wireless applications, like adding a light switch to control a wireless lamp for those installations where you can't run any wires (like in an existing cement wall). However, at the time of inception, they were like $75 for the switch, and another $75 for the damn lamp socket! Guess they're a bit cheaper now?
Charlie