No, I don't want to sign up for your newsletter — horrible uses of exit overlays
When a user moves their mouse from the middle of the page toward the navigation bar — presumably to abandon the page — there are technologies which can track this behavior and trigger a “mouse-out” alert. While this UX element (from companies such as Crazy Egg and Rooster) has great potential, I’ve found it far too common that websites use this to overlay huge pop-ups across the entire screen as a last-ditch effort to convert users. The exit-intent overlay has to have be...
Source: katsnyderux.com