As far as I understand (and I could be wrong), your machine does not actually generate money, but merely defers payment until some future date. It does so by essentially exploiting a bug in the Kindle + Credit Card system, and it has an upper limit of whatever your max credit line is.
We could perhaps consider it a time value generator limited by max credit. This could be reasonably analogized to a perpetual motion machine with an ongoing finite output.
We could perhaps consider it a time value generator limited by max credit. This could be reasonably analogized to a perpetual motion machine with an ongoing finite output.