One of the big advantages of SMS is that you are limited to 160 characters (in reality less, once you’ve added the opt-out ‘footer’). This means you must focus on the content of the message, not get distracted by images or links. Sure, you can write more than 160 characters, which sends multiple messages, and most networks/phones will put the messages back together, but when you hit high volumes, your costs will soar, and your members’ attentions will wane. Let’s stick to one SMS per message.
So, by its nature, SMS is simpler than email or post, which is good. Personalising the content is important, but given the limits already mentioned, first name or salutation is usually enough. You might use segmentation; have a different message for male or female, or different age groups, but the only other form fields you might use are for an appointment reminder, e.g. your induction/review/appt tomorrow at 10:30.
The key point in any member comms is the ‘Call to Action’.