Is there a way to create a link in a campaign that has been sent that allows a contact to opt-in to another email list with just one click? So this contact would receive an email, click on the link to sign up for this other list, and their email would be entered in automatically so they wouldn't have to re-enter it.
If you don't want to use a Landing Page to have the contact opt-in to a new list, you can use our Click Segmentation function to add them to different lists. You could create a link in the email to a PDF that states: "Thank you, you have been added to the new list for... etc." Then you would enable click segmentation on that link.