Sometimes they may be cheaper as prices continue to decline in today's market. There are no additional monthly fees to this service outside of FCC mandated taxes that one must pay under any long distance service. There are no minimum requirements nor minimum charges for this service. No Limit Calls are billed in full minute. Regular Cards with service can range from 12-15 cents a minute, depending on your state.
Advantage is that they bill in six second increments and that there is no limit of time.
Billing goes directly into your long distance bill.