If someone had this service of Patrick's, and then they had "some" customers on it, and other not, then it becomes an administration nightmare. Your staff would still have to take the time to look-up everyone and see who's getting called and who's not, and it's one more thing to keep track of. This burns a hole right through the benefits of automation.

Or just ask the people when they make the appointment if they would like a reminder SMS.

Not to put too fine a point on it, but, as a customer, I don't "need to recognize" anything.

If you don't realize that not showing up for an appointment is extremely discourteous and more importantly costing someone money, then yes you do have something you need to recognize.

Does someone seriously disagree that not showing up for an appointment is discourteous and costs someone money?

Yes

Why?

Because thats what appointment means. How would a customer feel if the service provider books say 5 customers at the same time and provide services to only one.

When you book an appointment with a service provider, service provider cannot book anyone else, EVEN if some other customer is interested to obtain their services at the same time.

You lost me there. You said that it is not discourteous and doesn’t cost someone money when the customer doesn’t show up to the appointment, right? What does this answer have to do with that?

Not to put too fine a point on it, but that's exactly the attitude that keeps companies and customers pissed off at each-other.