Private Marketplace (PMP): Definition and How It Works

Publishers regularly hold back top-tier placements for an invited group of buyers via Private Marketplaces (PMPs), preferred deals, or programmatic guarantees. While each format has its place, PMPs offer a unique balance of exclusive access and competitive auction pricing.

Below, we cover how PMPs work, where they fit alongside other deal structures, and when to use them.

What Is a Private Marketplace (PMP)?

A Private Marketplace (PMP) is an invitation-only programmatic auction where a publisher grants a select group of advertisers access to bid on premium inventory in real time, using a unique Deal ID instead of open bidding. A PMP is initiated by the publisher, not the buyer.

Its core characteristics are:

• Access is gated, but pricing isn’t. Publishers control who gets an invitation, but once inside, the bidding runs on standard real-time auction mechanics.
• Floor prices, not fixed rates. The publisher sets a minimum CPM, but invited buyers still compete against each other. This dynamic auction model is what separates PMPs from preferred deals, which rely on fixed, pre-negotiated rates.
• One-to-many competition. While a preferred deal is a direct 1-to-1 arrangement between one buyer and one publisher, a PMP allows multiple invited advertisers to compete for the same inventory.
• Built-in fallback options. If no invited buyer meets the floor price, the publisher can release the impression to the open exchange rather than letting it go unsold.

Want to understand the underlying technology? Read our overview of Real-Time Bidding (RTB) and Open Exchange.

Types of Private Marketplaces

PMP deals differ depending on two things: the number of publishers behind the Deal ID and the duration of the setup.

• Single-publisher PMP. The classic form: one publisher, one curated buyer list, one pool of inventory. This is what most of the mechanics above describe. It gives buyers the most control over context and brand adjacency. In practice, these deals rarely underdeliver because the inventory is weak. They underdeliver because the setup is too tight: a floor above where buyers’ bids land, plus several layers of targeting on top of the Deal ID, can shrink the addressable pool to almost nothing. When a deal isn’t spending, check in this order: deal approval and seat ID sync, floor versus bid, targeting overlap, then format and size.
• Curated/aggregated PMP. An SSP, data provider, or curation partner bundles inventory from multiple publishers that meet a shared quality, brand-safety, or audience bar, then offers it under a single Deal ID to a broader set of buyers. This trades some of the publisher’s direct control for buyer-side scale and simplicity. It solves the scale problem single-publisher deals can’t, especially in fragmented channels like CTV and DOOH. The trade-off is visibility. Before activating, ask which publishers sit behind the Deal ID, whether reporting is available at publisher or domain level, and how many fees sit between you and the publisher. A curated deal is only as good as its curation criteria, so question them rather than assume them.
• Standing vs. spot deals. A standing PMP is an always-on Deal ID a buyer can activate repeatedly across campaigns. A spot deal is negotiated for a single, time-bound flight, such as a product launch or seasonal event, and is typically retired once it ends. Standing deals reward patience: pacing, frequency, and optimization learnings build over time, and campaigns launch faster because the setup already exists. Spot deals carry timing risk, because approval, setup, and testing can consume a large share of a short flight. Get the deal live and tested with a small budget before launch day, set a clear end date, and retire the Deal ID cleanly so unused deals don’t linger in the buying platform.

These structures combine. A single-publisher deal can be standing or spot, and so can a curated one.

What Are the Benefits of a Private Marketplace (PMP)?

For advertisers, a PMP gives you direct-deal quality control without sacrificing the speed and scale of programmatic buying. For publishers, it’s a way to compete for premium demand without exposing top-tier inventory to the price unpredictability of the open exchange.

• Brand safety and control. Because advertisers are pre-vetted and the environment is known, the risk of ads landing next to irrelevant content drops compared to the open auction.
• Access to premium inventory. Publishers reserve their strongest placements, such as homepage takeovers, high-attention formats, top-tier content, for PMP buyers rather than the open market.
• First-party data matching in a closed environment: Advertisers can overlay their audience data onto a publisher’s user base without exposing it to the open exchange.
• More competition than a preferred deal: A PMP allows multiple buyers to bid at once, while a preferred deal is limited to single-buyer access. For publishers, bringing more demand to the same inventory helps support higher floor prices.
• Transparency. Both sides know exactly which publisher and buyers are in the deal; a completely different experience from bidding blind on the open exchange.

How Does a Private Marketplace Work?

A PMP deal moves through six steps, from setup to the individual bid decision:

1. The publisher creates the deal in their supply-side platform (SSP), defining the inventory in scope, a floor price, and any targeting or creative restrictions.
2. The SSP generates a Deal ID – a string carrying the floor price and targeting metadata, per the OpenRTB pmp object described above.
3. The Deal ID is shared with each invited buyer and entered against their seat in the buyer’s DSP, so the system recognizes it when it appears in a bid request.
4. When a matching impression becomes available, the bid request is flagged with the Deal ID and sent to the invited buyers’ DSPs.
5. Each buyer’s DSP decides whether to bid, evaluating the impression against its targeting criteria and bidding at or above the floor if it wants the placement.
6. The auction resolves among the invited bidders. If no eligible bid clears the floor, the publisher’s settings determine whether the impression is released to the open auction or goes unfilled.

For a side-by-side of how this compares to fixed-price and guaranteed structures, see the full comparison table on our Preferred Deals glossary page.

PMP Across Channels: Web, CTV, DOOH, Audio

While PMPs began in web display advertising, invite-only, Deal ID-based buying has since become foundational to how premium inventory is traded across every channel Perion operates in.

Digital Out-of-Home (DOOH)

PMP-style buying was central to bringing DOOH into programmatic in the first place, since screens are a naturally premium, high-scrutiny format where publishers want a curated buyer list.

“PMPs buying have been core to scaling programmatic DOOH. Enabling PG with Display & Video 360 gives buyers a tool that helps deliver with full confidence, especially in moments of inventory constraints, premium placement selection, hyper-targeting and short delivery windows.”

— Chris Allison, VP Programmatic Marketplace, Perion

That capability now runs at real scale: Perion’s programmatic guaranteed DOOH offering with Display & Video 360 is available across Perion’s full global DOOH supply footprint: over 590 media owners on 1.6 million screens across 40+ countries. See Perion’s DOOH channel for more.

Web

PMPs are most standardized across web display and video. Because core mechanics like Deal IDs, floor prices, and buyer seat lists originated here, web inventory aligns seamlessly with standard SSP and DSP tooling.

CTV and Audio

In CTV, PMP deals work the same way, but the targeting layer changes: instead of cookies, buyers target at the household or device level, and the “premium” inventory is a specific network, show, or ad pod position rather than a page. Because CTV inventory is scarcer than web display, a curated buyer list also helps publishers avoid saturating a viewer with the same ad across an entire pod.

In streaming audio (podcasts and streaming radio) PMP deals are used for premium ad slots or companion display units running alongside the audio player. Since audio inventory can’t carry a traditional cookie-based identifier, PMP buyers here lean more heavily on contextual signals (show, genre, content category) and publisher first-party data than on the audience data matching common in web PMPs.

What Are PMPs’ Limitations?

The most important limitation is one PMP shares with the open auction: it doesn’t guarantee volume. A floor price sets a minimum, not a commitment. If invited buyers don’t bid, or don’t bid enough to clear it, the impression isn’t delivered on the terms either side wanted.

This is exactly the gap that guaranteed structures exist to close. In DOOH specifically, 75–80% of ad spend is still booked via insertion orders because buyers demand a level of delivery certainty that auction-based models, including PMPs, cannot offer.

For more on how Perion approaches this on the supply side, check Demand Manager and Auction Optimization.