In the early 90s our office paid an additional fee to send text messages to our pagers. The idea was if you were out in the field and a call came in for service nearby the secretary could just text you the instructions via her desktop.
All she ever typed was, “call the office” so they canned it.
At first all we could send to pagers was our callback number. Later we moved to text pagers which allowed us to send 150 characters, with contact information, a basic problem description, etc. The reps could also acknowledge the message with the pager. That was much better.