As a publisher today, simply having great ad inventory isn’t enough. The real game is how well you connect that inventory to demand, and that’s where the right SSPs for publishers and ad exchange partners make all the difference. The best platform for publishers doesn’t just plug you into an ad network; it helps you […]

As a publisher today, simply having great ad inventory isn’t enough. The real game is how well you connect that inventory to demand, and that’s where the right SSPs for publishers and ad exchange partners make all the difference. The best platform for publishers doesn’t just plug you into an ad network; it helps you manage multiple ad sources, optimize ad placements, and protect ad quality so you can sell ad space at the highest possible value.

In this guide, I’ll walk through the top SSPs and side platforms that truly help publishers in the DOOH advertising space. These are the advertising platforms that provide publishers with smarter tools for ad monetization, from advanced header bidding setups and support for diverse ad formats, to tight integrations with Google Ad Manager and other major ad platforms. We’ll look at how each platform offers ways to connect publishers with premium buyers, boost ad revenue, and give both publishers and advertisers more control over how DOOH ad inventory is packaged, traded, and measured.

Whether you’re just starting to explore programmatic DOOH or looking to upgrade your current stack, this breakdown of leading SSPs will help you choose the right partners to allow publishers like you to scale smarter, not just louder.

Vistar Media 

If DOOH programmatic advertising had a “safe choice with serious muscle,” it would be Vistar Media.

Vistar is both an SSP and a full DOOH ecosystem provider (with a DSP and ad server). That matters because:

• On the supply side, it aggregates a massive amount of inventory: roadside billboards, transit, malls, gyms, airports, place-based screens, and more.
  
• On the buyer side, its own demand-side platform plus integrations with major omnichannel DSPs help ensure demand is not a bottleneck.
  
• Its ad server is built specifically for DOOH, so publishers can make smarter decisions instead of retrofitting web tools.
  

Where Vistar stands out is in audience and measurement. They’ve invested heavily in geospatial and mobility data, think audience segments built from movement patterns and visitation behavior, rather than just “a screen in this ZIP code.” That makes it easier to:

• Build campaigns around real-world behaviors (e.g., “frequent QSR visitors,” “gym goers,” “airport travelers”).
  
• Run brand studies and footfall analysis to prove DOOH impact to skeptical clients.
  

Pubmatic

Pubmatic is all about making DOOH feel like just another programmatic channel to the point where, inside many DSPs, DOOH via Pubmatic looks almost native.

Its core differentiator: true “OOH-as-a-channel” integrations with major omnichannel DSPs. Instead of clunky custom pipes, Pubmatic helps DSPs treat DOOH with:

• Standardized data and reporting alongside display, video, and CTV
  
• Consistent deal structures and private marketplaces
  
• Granular controls for buyers who are used to digital, not OOH
  

From a supply-side perspective, that means:

• You’re plugged into big brand and agency budgets that already live in those DSPs.
  
• Your DOOH inventory can enter omnichannel RFPs instead of being siloed in “OOH-only” buys.
  

Pubmatic is especially attractive if:

• You manage premium, urban inventory (street furniture, transit, large-format screens) and want to be included in brand storytelling and omnichannel plans.
  
• Your buyers keep saying, “We’ll only run it if we can buy it through our usual DSP.”
  

Magnite

Magnite has carved out a reputation as a global, data-rich DOOH SSP with a strong presence across North America, Europe, APAC, and LATAM.

Its strengths are:

• Global supply footprint: Not just big US markets. You’ll find Magnite inventory across many international cities and regions, which is key for global brands or tourism-heavy campaigns.
  
• Advanced audience targeting: Uses mobile location data and other signals to help buyers build audience segments and then activate them against DOOH screens at relevant times and places.
  
• Programmatic flexibility: Supports open exchange, PMPs, and direct programmatic deals, so publishers can tailor their monetization strategies.
  

For media owners, Magnite is compelling if:

• You’re expanding into multiple regions or already operate an international network.
  
• Your clients prioritize data-driven planning and attribution (footfall, store visits, etc.).
  

VIOOH 

VIOOH grew out of JCDecaux and still carries that DNA: premium DOOH inventory, especially in transit and urban environments.

Its distinctive characteristics:

• Deep roots with major OOH media owners, particularly in airports, transit systems, and high-traffic street furniture.
  
• A strong emphasis on curated, high-quality environments—screens where brand safety and context are major selling points.
  
• Tight integrations with leading DSPs so buyers can easily access premium, brand-building placements.
  

If your network is:

• Heavy on transit, airports, or city-center furniture.
  
• Focused on brand campaigns rather than pure performance, VIOOH is worth serious attention.
  

Broadsign Reach 

Broadsign is widely known for its content management software (CMS) used by many DOOH networks. Broadsign Reach is their SSP/exchange layer that connects those screens to programmatic demand.

Why that’s powerful:

• If you already use Broadsign as your CMS, plugging into Reach gives you an integrated stack: scheduling, delivery, and programmatic monetization, all in one ecosystem.
  
• Broadsign Reach aggregates inventory from a large number of Broadsign-powered networks, creating a scale that attracts buyers.
  
• They’ve put a lot of work into operational tools: creative approvals, campaign control, and yield optimization designed specifically for DOOH.
  

Broadsign Reach is especially attractive if:

• You’re a mid-sized or large network on Broadsign CMS and want to ramp up programmatic without stitching together multiple vendors.
  
• You care about tight end-to-end control over how ads are delivered and reported.
  

OpenX

OpenX approaches DOOH with more of a marketplace and self-serve mindset. It’s often praised for being approachable to digital marketers who are new to out-of-home.

What makes OpenX distinct:

• A user-friendly platform that lets brands and agencies discover screens, plan campaigns, and activate fairly quickly.
  
• A broad, mixed inventory set: roadside billboards, rideshare cars, urban panels, retail locations, and more.
  
• A strong focus on making DOOH accessible for mid-market and challenger brands—not just huge enterprise budgets.
  

For media owners, that translates into:

• Access to a diverse pool of buyers who might not be traditional OOH specialists.
  
• Additional incremental spend from test-and-learn digital teams who appreciate simplicity and quick activation.
  

Microsoft Monetize

Monetize  isn’t a DOOH‑only company, but that’s precisely its advantage. Its SSP and DOOH capabilities sit inside a broader omnichannel ad stack that touches display, video, native, and CTV.

On the DOOH side, Monetize stands out for:

• Helping DOOH inventory appear in large omnichannel campaigns planned through Microsoft’s DSP and partner DSPs.
  
• Strong data and identity capabilities carried over from the wider Microsoft ecosystem, enabling audience-based planning and measurement.
  
• Participation in industry standards efforts aimed at normalizing programmatic DOOH buying and selling.
  

For publishers, the key benefit is access to big-brand, data-driven programmatic buyers who might not think of DOOH first, but will happily add it when it’s one click away inside a familiar platform.

Others Worth Having on Your Radar

Depending on your region and vertical, you’ll also encounter:

• Outfront / Lamar / Clear Channel programmatic offerings – Often combining direct sales with programmatic pipes via partners like Vistar or Broadsign.
  
• Specialized regional SSPs and exchanges – Particularly in Europe, APAC, and LATAM, where local players can offer better relationships, niche inventory, or regulatory fit.
  

These SSPs may not be “universal best” SSPs, but can be the strongest option in a specific geography or vertical (e.g., healthcare networks, malls, rideshare, etc.).

How to Choose the Right DOOH SSPs for Your Situation

There’s no single “best” SSP, only the best fit for what you and your buyers are trying to achieve. A practical way to narrow it down:

Start from your inventory and buyers

• Are you premium transit/airport? Look closely at VIOOH, Pubmatic, and Vistar.
  
• Are you a large multi-market network? Magnite, Vistar, and Broadsign Reach stand out.
  
• Are you on Broadsign CMS? Reach is the most natural route.
  
• Want more mid-market digital buyers? OpenX is a strong complement.
  

Think in terms of portfolios, not a single SSP

• Most serious networks work with 2–4 major SSPs.
  
• That mix lets you tap into different demand pools (omnichannel DSPs, DOOH specialists, mid-market buyers).
  

Evaluate beyond buzzwords

Focus on:

• Geography and coverage that matches your screens
  
• Depth of integrations with the top DSPs your buyers already use
  
• Reporting, attribution, and support (especially DOOH-specific expertise)
  
• Operational overhead: how hard is it to manage deals, creatives, and approvals?
  

Pilot before you fully commit

• Run time-bound tests with clear KPIs: fill rate, eCPM, incremental buyers, operational lift.
  
• Compare performance by segment: format, location type, and time of day.