Unsubscribe rates track when you’ve finally lost permission for good. When someone unsubscribes from your list, it means they’ve gotten to the point where they’d like to formally revoke permission and never hear from you again. Marketers tend to focus on unsubscribe rates as the ultimate measure of when permission is lost. But the truth is, you probably lost permission far before your subscriber reached for that unsubscribe button.
Some ad platforms will ask more of your landing pages than others, when running ads. For example, AdWords is much stricter, when compared to Facebook. AdWords typically requires that you do not have a ‘thin,’ site that is designed solely to collect leads. Because of this it might be a good idea to focus on using Facebook or Twitter, to begin with.