Everybody hates exit popups -- those windows that used to hang around after you left a website. I say "used to" because just about every modern web browser and toolbar includes a popup blocker these days. Popup windows were too effective for their own good. They got overused, and therefore, they got blocked.
Of course, the perpetrators of popup windows are resourceful and not about to give up, so these days they're using Flash to open the popups, which gets around the popup blockers. But that's not the main thing I want to talk about today. Another "exit-popup-like" advertising method that's coming into vogue is what I call the "exit hover ad".
Hover ads (which aren't always shown on exit, BTW) are actually part of the webpage they're displayed on, rather than being a separate window, and perhaps because they're so directly connected to the website that's displaying them, and in fact obscure some of the website content until they're dismissed, webmasters appear to be more careful to ensure that the ads they display match the interests of their visitors. Perhaps the added "expense" to the user of hover ads will be the saving grace that prevents them from becoming hated like popup windows.
Exit hover ads are the most recent variant of hover ads. They're triggered when the user appears to be about to leave a website. They standard technique for triggering them is to track mouse movements and display the ad when it looks like the visitor is going for their browser's "back" button. With over 75% of visitors backing out of a typical website within 10 seconds of arrival (based on numbers I've seen), exit hover ads are a great way to catch the eye of people who wouldn't stay long enough to see your message otherwise without irritating those who do want to stay and read.
I'd been considering setting up exit hover ads on my site for a while, but hadn't gotten around to it until recently when I decided to create my own script to power exit hover ads, named "ExPop". Since I just got done late Friday, I don't have much yet in the way of results to report, though it looks like I may be seeing a jump in signups on one of my mailing lists using them. But I've read reports of people seeing sales increases of 33% up to a whopping 327% using this technique.