Companies who send periodic emails to their customers should do two things:
Provide an opt-out link that does not require the user to login to some account.
The worst experience I’ve had in this regard is Delta Airlines. I fly Delta, but got so tired of their SkyMiles emails that I decided to opt-out. This required hunting for my SkyMiles account login, and then hunting even more for the area in which you manage your email subscription. And then, worst of all, when I got there, I found that I was already unsubscribed. Dead end. What do you do in a situation like that? So I’ve blacklisted them in my spam filter. Sorry Delta.
Don’t make your customers go through this. Provide an opt-out link that doesn’t require logging in.
Provide the customer with the ability to opt-down, rather than opt-out.
I’m usually interested in receiving information from the companies I do business with — I just don’t want to hear from them every day. With most companies, you can either opt-in or opt-out. Unfortunately, a lot of the businesses I love (like REI) can’t contact me anymore, because I got tired of the volume. The Germanwings airline does it right. Here’s the choice I was offered when clicking their opt-out link. Rather than opting-out completely, I chose to allow them to contact me “once per quarter”. Nice!