The problem is with those "1cpm" calling cards is that they have lots of "gotchas" if you use 'em. Many have per call connection charges sometimes as much as 50 cents. And many of them hang on various fees such as weekly "maintenance" fees as well as other fees. You'll see these low rate calling cards advertised in convenience stores especially with imigrant population users. Below the "low rate" featured there will be a laundry list of conditions and fees that help to negate any real savings you could possibly have. As mentioned they will also charge exorbitant amounts for public phone access if only because they can (same rationalization that the mobile operators charge 20 cents per message for text messages if you are calling á la carte and don't have a messaging plan.