Twilio is a 3rd party SMS service you can use to send text messages to your customers. 

1. Sign up at Twilio - https://www.twilio.com/. Basic text messaging starts at $0.0075 per message.
    
2. Sign up at Nucom - 

Programmers Note: You can easily send text messages for a variety of actions from the store. Look in cfcs/global.cfc for a basic code example.