Popunder traffic is inventory sold by the impression: a full browser tab or window that opens behind a publisher's site the moment a visitor clicks anywhere on the page, then waits, already loaded, for the user to close their active tab. It's priced almost exclusively on a CPM basis - commonly $0.30-$5.00+ per 1,000 impressions depending on GEO, device, and quality tier - rather than per click, which is what separates it from most other display formats.
That's the direct answer. Below is what makes traffic popunder traffic as a sourced, priced inventory type - not the full mechanics of running a campaign, which the TrafficSigma team already covers in Popunder Ads: What They Are, How They Work, and How to Earn From Them in 2026, the complete pillar guide to the format.
Popunder traffic advertising: how it fits the rest of your media buy
Popunder traffic advertising sits alongside push, native, and in-page push as a standard self-serve inventory type - the difference is the placement mechanic (a full tab behind the active window) and CPM-first pricing. "Pop traffic" is common shorthand for the same inventory; "popup/popunder traffic" loosely combines the front-loading and back-loading variants, but popunder is the more widely supported today.
It's sourced almost entirely from publishers who can't monetize with standard banner/display units - download portals, streaming/file-sharing sites, and adult content are the classic sources, plus general-content sites adding it as extra revenue. A popunder ad network aggregates this across thousands of publisher placements into one buyable feed, targetable by GEO, device, OS, and carrier - TrafficSigma's own network runs 4B+ daily pop impressions across 248+ GEOs this way.
Popunder traffic quality: the signals that actually move it
Sold as raw impression volume, quality varies far more here than in click-based formats - check these signals before trusting any CPM quote:
- Fraud and bot filtering: real-time detection of non-human traffic; unfiltered pop feeds are the easiest inventory type to pad with junk volume.
- Frequency capping: how many times one user sees a popunder per window (commonly one to a few per day) - uncapped feeds inflate impressions without adding reach.
- Unique users vs. raw impressions: a feed of mostly unique visitors beats one re-serving the same users, at an identical CPM.
- Source vetting: vetted, premium publisher sources versus an open, unmoderated exchange.
- Post-click behavior: bounce rate after the popunder loads - a quick bounce signals mismatched targeting, however cheap the CPM.
A quality-filtered CPM almost always sits above an unfiltered, bulk-volume quote for the same GEO - that premium is the cost of the filtering above, which is why "cheapest CPM" is the wrong first filter for a source.
Get pop/popunder traffic from $1.00 CPM with TrafficSigma!How popunder traffic is priced and measured
Popunder is a CPM format, not CPC or CPA - the advertiser pays for the impression itself, win-or-lose on conversion, unlike push or native, often bought on CPC. CPM scales with GEO tier and device: Tier-1 desktop (US, UK) commands the highest market-average rates, commonly in the $3-$6+ range at strong quality and running higher still on some networks; Tier-2/3 GEOs and mobile can run under $1, with TrafficSigma's own pop/popunder feed starting from $1.00 CPM. Note this reflects typical market pricing, not any single network's floor CPM - floor rates (the minimum a network will accept) are usually lower than what quality traffic actually clears at.
See TrafficSigma pricing and ad formats
What popunder traffic buys you that other formats don't
Popunder traffic is a distinct inventory type, not just a synonym for "popup ads" - aggregated from publisher placements that load a full tab behind the user's active window, priced by CPM rather than click, and separated from junk volume by fraud filtering, frequency capping, unique-user ratios, and source vetting. Buy it on quality signals first and CPM second, and measure success on cost-per-converted-user, not the sticker price.
Ready to move from definition to launch - targeting, budgets, publisher-side earning models, and compliance? The pillar guide has the full walkthrough: Popunder Ads: What They Are, How They Work, and How to Earn From Them in 2026.
