First, let's talk about how to set up a Coupon Image using the Coupon Builder.
Step 1: Open up the Coupon Builder section through the Left Side Panel in the software. Then click + New Coupon.
Step 2: Name your Coupon Image, then select the campaign that you'd like to connect to this coupon.
Step 2B: Enter the Coupon Keyword which will be used to subscribe users via SMS when accessing the coupon image via mobile phones. (More info about this below)
Step 3: Upload the image from your local drive/computer, and set its dimension if you want to customize it. But you can just stick with "auto".
What about the Keyword?
Now, let's continue with the Keyword. When a user taps on the image while using a mobile phone, the image will send an action command to the phone to open up its Messaging App and auto-fills the textbox with the keyword to be sent to the campaign number. Here's an example: