In the world of online marketing, double opt-in is used to describe a situation where a visitor subscribes to you by signing up with their e-mail. Webmasters provide the visitor the “option” of joining a membership OR accepting your autoresponder messages. There is a single opt-in or a two factor “double opt-in” where the visitor must click on a link within the first email.
Reviews and Affiliate Marketing Tips
Recurring Income, SEO, Blogging and More