Max wrote:

People have been selling things like this for decades.

Precisely.

I suspect that they offer "money back if not satisfied" and rely on
people not bothering to send it back. Also it *might* be better than
some indoor aerial setups, especially FM radios which rely on a piece
of wire dangling.

There's one particular magic aerial that's appeared from time to time
over the last two decades that just consists of a piece of wire with a
solid plastic block moulded on the end. What you get for your money is
a piece of wire dangling with a weight on the end :-).

One reason these scams continue to work is that the goods are priced
just on the right (or wrong) side of the "I've been conned but I can't
be bothered to do anything about it" barrier.

--
Andy