Pop-Under Ads
Opens behind the window — seen after you finish browsing.
Overview
Pop-under ads open in a new browser window or tab behind the page the user is currently viewing. Unlike pop-ups, which appear on top and interrupt immediately, pop-unders stay hidden until the user closes or minimises their main window — surfacing the ad at the end of the session. They deliver cheap, high-volume impressions, but are widely regarded as intrusive and low-quality.
How it works
A script on the publisher's page triggers a new window on user interaction (a click anywhere on the page often satisfies browser pop-up rules), then immediately sends it behind the active window using JavaScript focus controls. The pop-under loads the advertiser's full landing page. Modern browsers increasingly block these, so networks rely on workarounds that are an ongoing cat-and-mouse with browser vendors.
Common uses
- →High-volume, low-cost traffic campaigns
- →Affiliate and CPA offers
- →Markets where cheap reach matters more than quality
- →Adult, gaming, and download verticals
Pros & cons
Pros
- ✓Extremely cheap impressions
- ✓Full-page creative canvas
- ✓High raw volume available
- ✓Less immediately disruptive than pop-ups
Cons
- ✗Widely seen as intrusive and spammy
- ✗Aggressively blocked by modern browsers
- ✗Very low engagement and trust
- ✗Can harm brand reputation and site quality scores
Live examples
Simulated mockup — illustrative, not a real ad
Pop-under behaviour
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The page you actually visited
Click anywhere on a real page can trigger a pop-under.
↑ The ad loads behind your active window — surfacing only when you close it.
Live ad — served by Google AdSense
And here's the real thing: an actual ad served into the page. What appears depends on the advertiser auction and your browser — it won't always match the format above.
Ad slot
Awaiting AdSense ad unit
Key metrics
Avg. CTR
Effectively n/a
Pricing model
CPM (very low)
Typical CPM
$0.10–$2
Viewability
Low / disputed
Advertisement
Ad slot
Awaiting AdSense ad unit