This is a sample use case for simple SMS broadcast marketing.
 
Scenario:
 

• A restaurant owner would like to inform regular clients of a Christmas promotion.
• To comply with local regulatory, if a client replies “UNSUB” the client will be considered as opted out and no SMS shall be sent to the client in the future.

 
Broadcast Message:
 
<ADV> X’mas promotion at Yummy Restaurant. First 100 customers get 25% off total bill. Reply UNSUB to opt out.
 
This use case can be set up as an automated task. Once the task has started, the message will be sent out to all contacts added to the task. If any of the recipients replies with UNSUB as the first word of the message (not case sensitive), the contact will be automatically tagged as opted out. No SMS will be sent to an opted out contact until the tag is manually removed by un-checking the Opted Out box on the contact’s Contact Details page.
 
This sample use case can be created under Automated Tasks -> Add New: