To use your own analogy -- it would be as-if your phone provider charged you to call me (they do), my phone provider charged me to receive the call (they do), then my phone provider charged you for making the call (they don't).
Actually, they do (on that last point). Which is why Google Voice won't route calls to certain numbers. It's called a termination fee, which works like this: I pay my local phone company, and also pay a long distance carrier. When I call you, your local phone company charges the long distance carrier a fee, which that carrier then passes on to me. (Well, it used to work this way, but almost everything is flat rate now).
