Originally published on my site, arafatcro.dev/guides.

You copy the exit-intent snippet, it fires nicely when the cursor heads for the close button, and you ship. Then you check the data and half your traffic never triggered it, because they were on phones and a phone has no cursor to chase. Exit intent is not one trick. It is a different signal on each device, fired once, and built so it does not become the thing people leave over.

The trick everyone copies

The standard snippet listens for the mouse leaving the top of the page. When the cursor crosses the top edge, heading for the tab bar or the close control, you call it intent to leave and show your overlay. On desktop it works.

The problem is that this signal only exists on a device with a pointer. On a phone or tablet there is no cursor, nothing ever leaves the top of the viewport, and that listener never fires. So the most common exit-intent implementation does nothing for anyone on a phone, which on a lot of sites is more than half the traffic. Nobody notices, because it looks like it is working on the desktop where you tested it.