Do you have any citations for that? I see people either signing up because they don't realize they have a choice because the button to say "No" is intentionally

Do you have any citations for that? I see people either signing up because they don't realize they have a choice because the button to say "No" is intentionally smaller and obscured, but then they mark the newsletters as spam, or simply throw them out. I also see lots of people adding fake addresses like "screw@you.com" just to get past them. Has anyone verified that they actually do some real amount of good for the business putting them up beyond the simple metric of "we got tons of signups for our newsletter after doing it!"?