What happens when someone who is already subscribed tries to sign up again?
Subscribers can sign up via AWeber forms multiple times. The subscriber will not be added to the list multiple times instead, when this happens additional information provided will be updated within that subscriber's information. This additional information can then be used for reference or for personalization in messages. This also allows for any tag automations that is set up for that form to be applied as well.
When they're already on the list, they will follow a different path upon submitting the form. Instead of receiving the thank you page, they will receive an already subscribed page that can be customized. This can be customized for both sign up forms and landing pages.