So we’ve faced this weird (imo) behaviour from some readers. They hit on Subscribe, become confirmed subscribers after they receive the confirmation link email and then unsubscribe from all our newsletters without even receiving a single email from us. Is there a way to make at least one newsletter necessary to become a subscriber? I just simply don’t get this flow—they leave their email, but unsubscribe from content before they even get any, so from the conversion quality point of view, this subscriber is useless…
Hope someone faced this as well 
Whether that behavior is ‘weird’ or not depends a lot on your setup.
If you require that website visitors register to access some of your members-only content online, then the behavior makes sense - they want to read your article online, but don’t want your emailed newsletter. There, the behavior makes sense.
But yes, if you are wanting sign-ups to lead to receiving an emailed newsletter that might lead to sales, these users are a bummer.
I /think/ it’s technically possible for a theme to only show content to users who are actually subscribed to the newsletter, but I am not aware of any themes that do this.
Yes that makes sense, however we don’t have any members-only articles whatsoever, so all content is accessible without subscription, that’s why I can’t really grasp why share en email and then instantly unsubscribe… 