More Nigerian phone protocols

I initially scratched my head when I saw phone companies advertising their new area codes (imagine AT&T owning all 456 area code #s and advertising the fact). It’s because people take advantage of intra-network discounts/free calls by having phones on different networks, and some phones can even carry multiple SIM cards and work on multiple networks at once. When you get someone’s number, you put it in one phone or another depending on what network they are on. Carriers want you to know their area codes so that you know which friends use their network and thus get a phone on the same network.

Nigeria is also one of the places that pioneered per-second billing.