Exit-Intent Popup
A popup that appears the moment a visitor's mouse moves toward the browser's close or back button, the instant before they would otherwise leave.
An exit-intent popup watches cursor velocity and direction on desktop (and scroll-up speed or a back-button press on mobile) to guess that a visitor is about to leave, then shows one last offer, discount, or signup form before they go.
It works because it never interrupts someone who is still reading. A popup that fires on page load competes with the content; one that fires on exit only competes with leaving empty-handed, which is a much easier ask to win.
The offer matters more than the trigger. A generic "Wait!" popup converts worse than one with a specific, relevant reason to stay: a discount code, a lead magnet tied to the page topic, or a shorter version of the form they were about to abandon.
See it in practice