A radio station transmitter does not suffer greater costs when more radios are tuned in. It just blasts that energy out in all directions, and your radio picks up a bit of it. This gizmo just collects that energy and routes it for other uses.
One of Neal Boortz's bits that I found particularly amusing was when he put down a particularly shirty, idiotic caller:
"
Ma'am, you might do me a favor. On the back or maybe the bottom, of your radio set, you will find a serial number.
If you will kindly give that number to Royal [the show's call screener], we can arrange to have your radio disconnected from our transmitter.
This would allow us to connect some deserving listener from our waiting list in your place; so your cooperation would be appreciated.
"