That’s a very good point. In cases like that, verified opt-in might be more appropriate.

This raises a more universal point about usability and user experience. You should plainly explain the status of an action a user has taken, what the steps in a process are and set expectations when action is required.

Cheers,
-Alex

Good tip, I would just add that the marketer should take into account who the audience is, and how tech-integrated they are. I’ve seen quite a few email marketing campaigns fail with a double opt-in because the visitors weren’t familiar with them and didn’t know they had to take an action…resulting in a large number of lost opportunities.