Opt in Link: Mural

I was registering for a webinar on Mural.com
After I entered my email address a message and hyperlink appeared.

"Looks like you've opted out of email communication. Click here to get an email and opt back in."

This is great. This serves business needs and user needs without being obstructive. 



I wonder if they discussed just placing a checkbox there to have the user opt back in.
Why did they choose to go with a link that triggers an email?
Anytime you leave the burden on the user you risk missing the goal.
Nevertheless, nice work!

Email Updates on StrengthsFinder

Email 

The first checkbox after the form was this:

-->

I’d also like to be among the first to know about new Gallup offerings and services. I understand that I may subscribe from these offerings at any time.

Email updates on Zola.com

After completing an order for a friend's wedding gift I am rightly prompted to let them know where I would like my order updates sent. 

Of course! Here is my email address. 

This is a great moment (per business needs) to grow their promotional email list. 

The wording here is key. 

Most users will assume the checkbox text "Yes, send me email updates from Zola" is referring to the same thing as above "order updates"

MS Flow: Get Started (and agree to terms) button

When logging in to MS Flow for the first time you must select your country.
Then when you click Get Started button you are also agreeing to the terms.

They let you know that they will send you promotions and that you can unsubscribe at any time.
They conveniently place this message in small type, and far from the button.
It would seem they are balancing business goals and user goals very well.