Is the free call really free?

  is the free call really free?

free phone calls in the 2G/3G/4G network for a minute to consume about 300K of traffic; When the time to consume less than 1k/hours; After successful registration, the first automatic backup of the contact needs to consume a small amount of traffic (Backup 300 contact people need traffic 60K or so); Add/Remove/ Changes are automatically backed up when you modify a contact, and a single contact consumes 0.2K of traffic.

At present, the carrier traffic rate of 1K roughly between 0.0001 to 0.0005 Yuan, based on this price conversion, the use of micro-letter telephone in the 2G/3G/4G network under the call for a minute to spend about 0.03 to 0.15 yuan.