"it's like PayPal without the fees."
easy. (forget who first said that - sorry. it wasn't me.)
It kinda reminds me of the Einstein quote explaining how radio works.
"You see, wire telegraph is a kind of a very, very long cat. You pull his tail in New York and his head is meowing in Los Angeles. Do you understand this? And radio operates exactly the same way: you send signals here, they receive them there. The only difference is that there is no cat."
--Albert Einstein, when asked to describe radio.
Long cat is looooooooooooong.