The pop-up opt-in displays a ligthtbox pop-up on your website. Within the pop-up is a form that visitors can use to subscribe to your mailing list. Pop-ups are highly effective at collecting emails due to the simple fact that they cannot be ignored. These pop-ups can be placed anywhere on your website, and they can also be triggered based on unique user interactions. When combining pop-ups with triggers, you can make your opt-in form even more effective by asking visitors to subscribe at the optimum moment (such as when they have finished reading a post, after they have posted a comment, or after they have purchased a product).