A custom field can be entered into your message to personalize it for each contact. The contact enters it upon sign-up via your HTML form, or you import it to the account along with the contact’s name and email. You can use this customized information in the messages you send out, i.e. it can be the name of the city the contact resides in. Personalizing your messages by displaying custom information for every contact will help you increase the response rate.
In order to add a custom field, please go to Contacts >> Custom Fields.
