Thanks to everyone for their help for me and others too.
I like the idea of the exit-intent popup, as it doesn't interrupt the user experience, but my concern is that since more than 50% of Web traffic is on mobile, I believe there is no way to use them with a mobile device.
I have Ninja popups, and they have exit-intent popups, as well as the ability to disable them on mobile devices, AFAIK. The problem then becomes if you activate that feature, then you have no popup for more than half of your traffic.
So may I have your opinion on the best popup strategy?