Apple video phone how to charge
FaceTime costs only with the flow of the relationship, if the use of WIFI, is not a fee.
Apple's video between the use of FaceTime FaceTime seems to be only in the WIFI access mode to get through (I use each time in the WIFI), so completely free. If not the model then follow the operator traffic billing!
If the use of 3G or cellular data network (not all iphone cellular network or 3G can support FaceTime) generated costs associated with the operator, so the cost is not the same.