Outdoor advertising is increasingly used in conjunction with digital channels, which means that pricing models such as CPC, CPM, CPA, and CPV are appearing more frequently in discussions regarding OOH and DOOH. To value these investments fairly, it is essential to understand what each model measures and how they relate to the underlying logic of outdoor advertising—namely, reach and VAC (Visibility Adjusted Contacts).

CPM (Cost Per Mille) is the metric most closely aligned with outdoor advertising. In OOH and DOOH, it effectively represents the cost per thousand contacts or exposures within defined environments. When purchasing an outdoor advertising network—such as bus shelters, street furniture, city information panels, or standalone billboards—prices are often converted into CPM to enable comparison with other channels. In this context, the calculation is based on contacts modeled from traffic flows and site placement.

CPC (Cost Per Click) is not applied directly to classic outdoor advertising, as the medium is not interactive. However, an “effective CPC” can be calculated indirectly by tracking how OOH influences search volumes, direct web traffic, or QR code scans. This allows outdoor advertising to be valued in relation to digital response, even though the price paid to the media owner is based on contacts.

CPA (Cost Per Action) is an even more results-oriented metric. In relation to OOH and DOOH, it is often used in models that link exposure to actual sales, store visits, or other conversions. The outdoor investment is distributed across the number of measured actions within the target group. For DOOH—and specifically prDOOH—this can be integrated more continuously by optimizing campaigns toward areas and time slots with the lowest observed CPA.

CPV (Cost Per View) is primarily used in video media but can be applied to DOOH where you purchase a certain number of play-outs or verified impressions on digital screens. Here, the question becomes how long the creative is displayed and what the actual reach of each view is within the physical environment. CPV provides the most value when combined with knowledge of which outdoor environments and formats offer the best balance between visibility and cost.

Key Takeaways for Media Planners

For media planners, the conclusion is that the same financial metrics can mean something slightly different in outdoor advertising than in purely digital channels. CPM for OOH is based on modeled contacts, not logged ad-server impressions. CPC and CPA should be viewed as analytical tools rather than pricing models. By keeping these distinctions clear, it becomes easier to compare investments in OOH, DOOH, prDOOH, and other media in a structured way, ultimately choosing the best format for reach and impact within a given budget.

Why We Use Reach and VAC in Outdoor Advertising

In outdoor advertising, we prioritize Reach (how many people we reach) and VAC (Visibility Adjusted Contacts, i.e., how many actual, visible contacts we achieve). These are calculated by Outdoor Impact, which utilizes one of Europe’s most advanced and reliable frameworks, combining detailed data on ad sites, traffic flows, and travel patterns. This enables precise contact calculations for both analog and digital sites, based on the actual physical conditions of both the object and the recipient.

• VAC accounts for real-world visibility, such as placement, angle, distance, and duration of exposure, thus providing a more realistic measure than theoretical contacts alone.

• CPM in (D)OOH therefore represents the cost per thousand VAC—the price for genuine, likely noticed contacts.

Once reach and VAC are established, we can link these to digital KPIs:

• Uplift in traffic/search → can be interpreted as an indirect CPC.

• Uplift in sales/store visits → can be converted into CPA.

• Number of views on DOOH screens → can be expressed as CPV, always supported by VAC data to understand the true impact.