When should I use SMS vs. email?
Use a text message when you want to make sure a message is seen quickly; for instance, when the content is time-sensitive or extremely important. The message should also be as short and direct as possible. Examples include your initial welcome message, flash sale announcement, and any special offers. You could also use SMS to notify subscribers of certain transactions, like when their order is on its way or been delivered.
Use an email for longer-form content, including newsletters, and any messages that you want to reach the majority of your audience, such as a product launch. It is a good idea to send any important messages you sent by SMS via email to the rest of your subscribers.