I went to a restaurant with my wife a few nights ago. It was packed so we had to wait. The hostess took my phone number and texted us when our table was ready.
Just like that they were able to create a new communication channel with me.
The next day I received a text with a coupon to go back for a free dessert.
Text message appointment reminders are not only an effective addition to servicing your customers. They take the workload off a receptionist and if used properly can become a new marketing channel to increase purchase frequency.
Most scheduling softwares have this feature but few are utilizing them.