Platforms: SMS / Twilio
While Dexter's other platforms such as Facebook or Twitter offer power in the expressiveness of what you can do with them (e.g., prompting users with buttons), SMS's power lies in its ubiquity. You can pretty much count on your audience being on SMS.
Follow the step-by-step instructions found on the Platform configuration page to get started with deploying and launching a bot on SMS (you will create an account on a service called Twilio to do this, and take a look below for some detailed descriptions on concepts.
If a user ever messages your bot with language like "unsubscribe" or "stop," Twilio automatically handles the mechanism for you. Read more about how this works.
Twilio Messaging & Broadcast Policies
All broadcasts you send via Twilio must conform to their policies around messaging.
How much does it cost to use Twilio?
Twilio is an SMS platform that will accrue costs with continued usage. To use Twilio, you may use the provided trial number and trial account with Dexter, but the usage of these trial credentials will be rate-limited by Twilio. Your total invoice may vary depending on the phone numebr you choose to purchase and the number of messages your bot receives and sends. You can read more about fees associated with using Twilio on their pricing page.
Twilio has flagged me for sending a high volume of messages over a 10-digit number.
Twilio does not support broadcasting marketing messages from a long-code (10-digit number). Marketing messages can only be sent using shortcodes. Learn more about shortcodes here.
My SMS messages are not arriving in the right order.
Send/delay work very well in our system! However, once they reach Twilio - or, to be more precise, the telecom providers Twilio sends the information to - all bets are off. Twilio describes the problem and notes a semi-solution here. Increasing your delay MAY help, but there's sadly no way to ensure response order via SMS. Message order may vary depending on carrier.
My media files are not coming through on Twilio.
Total message size must be under 5MB. Twilio recommends keeping content size for each piece of media under 500KB. You can confirm if your message has succeeded or failed in sending by visiting the Message Log of your phone number on the Twilio console.