Having a prepaid PIN is like having virtually untraceable money. Going somewhere where you don't want your expenses and/or purchases tracked? Use the PIN. Want to keep your identity secret from a vendor? the Prepaid is the perfect tool.
You just use it on your pre-paid card you got from them with the pin number you can use as well. This goes with those pre-paid cards for cell phones minutes as well as using the pay phone when you do not have change.
