because people were already uaing sms when it was paid beforehand before smartphones were a thing. people just used to whatever the default was, especially since its not like everyone switched to a smart phone immediately after the iphone 3gs’ relase. sms was the default method to talk to people who were still using "dumbphones
39 cents/SMS. I remember this time. This does not explain why it has to be that specific protocol, though.
because people were already uaing sms when it was paid beforehand before smartphones were a thing. people just used to whatever the default was, especially since its not like everyone switched to a smart phone immediately after the iphone 3gs’ relase. sms was the default method to talk to people who were still using "dumbphones