SSP, DSP, and deal IDs: programmatic DOOH terms explained

Who's on which side of a programmatic deal? The question of SSP vs DSP comes down to that. A supply-side platform, or SSP, works for the seller, making ad inventory available to buyers. A demand-side platform, or DSP, works for the buyer, helping it find and purchase inventory. Deal IDs and private marketplaces are the arrangements that connect the two under agreed terms.

These terms came from online advertising and now apply to digital out-of-home as well.

What is an SSP?

A supply-side platform is software that sellers, such as publishers or media networks, use to offer their ad inventory to buyers programmatically. It packages inventory, sets rules and floor prices, and connects to buying platforms and exchanges.

In DOOH, the inventory is screen time. An SSP might offer plays on a set of screens in certain locations and times, according to the seller's rules.

SSPs also enforce rules the seller cares about, such as which advertisers or categories can buy, minimum prices and how inventory is described to buyers.

The SSP's job is to help the seller make inventory available efficiently while keeping control over who can buy and on what terms.

What is a DSP?

A demand-side platform is software that buyers, such as advertisers and agencies, use to purchase inventory across many sellers from one place. It lets buyers set targeting, budgets and bids, and manage campaigns across channels.

For a buyer, the appeal is consolidation. Instead of negotiating separately with each network, the buyer can plan and buy through one platform, including DOOH alongside other digital media where supported.

DSPs typically provide reporting across everything bought through them, which makes it easier to compare channels in one place. Each channel's measurement still depends on the data the seller provides.

The DSP's job is to help the buyer find the right inventory at the right price and report on what was bought.

How do deal IDs and private marketplaces work?

A deal ID is a code that identifies a specific agreement between a seller and a buyer. When a buyer's DSP sees inventory tagged with that deal ID, it knows the agreed terms apply, such as price and targeting.

A private marketplace, or PMP, is an invitation-only arrangement where a seller makes inventory available to selected buyers under agreed terms. Deal IDs are how PMPs are usually put into practice in the platforms.

An open marketplace, by contrast, makes inventory available to many buyers at once, often through real-time bidding, with less control for the seller over who buys.

PMPs sit between open marketplaces, where many buyers compete, and direct buys, where terms are negotiated one-to-one. They combine programmatic efficiency with more control over who buys and how.

How does this apply to in-store screens?

In-store screens can be bought in different ways depending on the network. NRS Digital Media campaigns can be bought directly or by PMP, with no forced networks or minimums. Campaigns can be activated by audience index, retail channel, SKU level, or geography down to the zip code.

Direct buys remain common in DOOH, especially for campaigns that need custom planning or close coordination with the network.

The specifics of a PMP setup, such as which platforms are involved and how deal terms are structured, vary and should be confirmed with the network. Ask the NRS Digital Media team how a PMP deal would be set up for your campaign.

Before buying programmatically, it's worth asking a few questions of any DOOH network. Which buying routes are supported? How are impressions counted? What targeting is available through each route? What reporting will you receive, and does it match what a direct buy would provide? The answers help decide whether programmatic or direct buying fits your campaign better. More about the network is on the NRS Digital Media site.